CN102329315A - Fluoro methoxyimino-substituted nalidixic carboxylic acid compound and preparation method thereof - Google Patents

Abstract

The present invention provides a kind of naphthyridone carboxylic acid compound containing fluoromethoxyimino substitution represented by formula (I) and its preparation method, as well as antibacterial pharmaceutical composition containing them, the compound represented by formula (I) or its medicine The structure of salt and hydrate is as follows:

Description

Nalidinone carboxylic acid compound containing fluoromethoxyimino substitution and preparation method thereof

technical field

The invention belongs to the field of medicinal chemistry, and relates to nalidinone carboxylic acid derivatives with anti-Gram-positive drug-resistant bacteria activity or a preparation method thereof, and antibacterial pharmaceutical compositions containing them; specifically, to 7-[(3- Methyl-)3-aminomethyl-4-(fluoromethoxyimino)-pyrrolidin-1-yl]naphthyridone carboxylic acid compound or its preparation method.

Background technique

Since the advent of nalidixic acid (nalidixic acid, J.Med.Chem.1962, 5:1063) in 1962, quinolones (including nalidixones) have developed into a class of broad-spectrum, Anti-infective chemotherapy drugs with high efficiency and low toxicity (Chinese Journal of Pharmaceutical Industry 2010, 41:456). Due to widespread use and irrational use of drugs, bacterial resistance to these drugs has increased rapidly, especially Pseudomonas aeruginosa among Gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA) among Gram-positive bacteria , Methicillin-resistant Staphylococcus (MRSE), vancomycin-resistant Enterococcus (VRE) and penicillin-resistant Streptococcus pneumoniae (PRSP) infections have become one of the thorny issues facing clinicians. People urgently need to find new quinolone antibacterial drugs with stronger activity against these drug-resistant bacteria to deal with these increasing drug-resistant bacterial infections.

In 1995, Sanchez et al. reported the synthesis and in vitro biological activity of a series of (5-amino-) 8-alkoxy fluoroquinolones with five or six-membered nitrogen-containing heterocyclic substituents at the 7-position (J.Med. Chem.1995, 38:4478), wherein the representative 7-(3-aminomethylpyrrolidin-1-yl)-8-methoxyfluoroquinolone exhibits broad-spectrum antibacterial activity.

In 1995, Chinese patent (CN: 95107008.8, 1995-06-15) disclosed a fluoroquinolone compound with the following general formula [A]:

And the substituent _R2 in the general formula is broadly defined, but _R2 does not include monofluoromethyl or difluoromethyl.

An excellent representative of the general formula [A] is gemifloxacin (gemifloxacin), which has been successfully developed and approved by the FDA for marketing in the United States. In addition to its broad-spectrum activity, its outstanding advantage is that its activity against Streptococcus pneumoniae is better than that of the marketed The disadvantage of other quinolone antibacterial drugs is that it is not active against clinically common Staphylococcus aureus (including the increasing number of MRSA), which limits its clinical application.

In 1995, Korean Patent 024002 (1995-08-31) disclosed a fluoroquinolone compound having the following general formula [B]:

And the substituent _R2 in the general formula is broadly defined, but _R2 does not include monofluoro or difluoromethyl.

DW286, an excellent representative of the general formula [B], has weaker activity against gram-negative bacteria than gemifloxacin, but better activity against gram-positive bacteria than gemifloxacin. According to reports, DW286 stopped further research and development after completing the phase I clinical trial. unknown reason.

In order to overcome the defects in the above-mentioned prior art, the inventors have carried out extensive research, designed and synthesized pyrrolidin-1-yl naphthyridone carboxylic acids with a fluoro/difluoromethoxyimino substitution at the 7-position compounds and their antibacterial activities were determined. Finally, it was found that, unlike the 7-[(3-methyl)-3-aminomethyl-4-(one-fluoro/difluoromethoxyimino)-pyrrolidin-1-yl]naphthyridone carboxylate Acid compounds have unexpectedly strong antibacterial activity against clinically important pathogenic bacteria. The in vitro activity of Staphylococcus aeruginosa and Pseudomonas aeruginosa including MRSE is 2->521 times that of the control drug ciprofloxacin, and 2-32 times that of gemifloxacin; against Staphylococcus aureus MRSA10-2, Staphylococcus aeruginosa The in vivo activities of MRSE10-4 and Pseudomonas aeruginosa 10-1 were 1.4-6.1 times that of ciprofloxacin and gemifloxacin.

Contents of the invention

The object of the present invention is to provide a class of naphthyridone carboxylic acid compounds represented by general formula (I) or pharmaceutically acceptable salts and hydrates thereof,

in:

R represents cyclopropyl, 2,4-difluorophenyl;

R ₁ represents H, CH ₃ ;

R ₂ represents CH ₂ F, CHF ₂ ;

X stands for H and F.

In the pyrrolidinyl part of the compound of general formula (I) of the present invention, the carbon atom connected to the aminomethyl group is an asymmetric carbon atom, so it can exist in the form of R or S or R and S mixed, and the present invention includes all of these Isomers and mixtures.

In the pyrrolidinyl part of the general formula (I) compound of the present invention, due to the presence of the 4-position oxime group, the general formula (I) compound can exist in the form of E-type or Z-type or E-type and Z-type mixtures, The compounds of general formula (I) of the present invention include all these isomers and mixtures.

The pharmaceutically acceptable non-toxic pharmaceutical salts of the compound of formula (I) of the present invention include salts formed with inorganic acids such as hydrochloric acid and sulfuric acid, and salts formed with organic acids such as acetic acid, trifluoroacetic acid, citric acid, horse salts of toric acid, oxalic acid, succinic acid, benzoic acid, tartaric acid, fumaric acid, mandelic acid, ascorbic acid or malic acid, and amino acids such as alanine, aspartic acid, lysine or salts with sulphonic acid Acids, such as methanesulfonic acid, p-toluenesulfonic acid salts.

The compounds of formula (I) of the present invention may also exist in the form of solvates (such as hydrates), therefore, these solvates (such as hydrates) are also included in the compounds of the present invention.

The present invention specifically includes the following compounds, and their pharmaceutically acceptable salts and hydrates:

1-cyclopropyl-6-fluoro-7-[3-aminomethyl-4-(fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4-oxo -1,8-Naphthyridine-3-carboxylic acid

1-cyclopropyl-6-fluoro-7-[3-aminomethyl-4-(difluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4-oxo -1,8-Naphthyridine-3-carboxylic acid

1-cyclopropyl-7-[3-aminomethyl-4-(one-fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4-oxo-1,8 -Naphthyridine-3-carboxylic acid

1-(2,4-difluorophenyl)-6-fluoro-7-[3-aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4- Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid

1-(2,4-difluorophenyl)-6-fluoro-7-[3-aminomethyl-4-(difluoromethoxyimino)-pyrrolidin-1-yl]-1,4- Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid

1-cyclopropyl-6-fluoro-7-[3-methyl-3-aminomethyl-4-(fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro -4-oxo-1,8-naphthyridine-3-carboxylic acid

1-cyclopropyl-7-[3-methyl-3-aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4-oxo Dai-1,8-naphthyridine-3-carboxylic acid

The present invention also relates to the preparation method of the compound of formula (I), as shown in Reaction Scheme 1.

Reaction route 1:

In Reaction Scheme 1, R, R ₁ , R ₂ and X are as defined above; R ₃ represents an alkyl or aryl group, preferably a phenyl group.

Including the following steps:

1) Add a base to an aprotic dipolar solvent, and conduct a condensation reaction between the compound of formula (II), the compound of formula (III) and the compound of formula (IV) at room temperature to 100° C. for 0.5 to 10 hours to obtain the compound of formula (V).

in:

R, R ₁ , R ₂ , R ₃ and X are as defined above.

This reaction is generally carried out in the presence of a base. In this case, in order to improve the reaction efficiency of the more expensive formula (III) compound, use an excess of reactant formula (II) compound and (IV) compound, such as relative starting material is equimolar to 5 times the molar amount, It is preferably equimolar amount to double molar amount. When excess reactants compounds of formula (II) and (IV) are used, the unreacted mixture remaining after the reaction can be recovered and reused in the reaction. The aprotic dipolar solvent used for this reaction is selected from N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide or acetonitrile; the base is selected from triethylamine, Sodium carbonate, sodium bicarbonate, potassium carbonate, sodium hydroxide, or potassium hydroxide.

2) Then place the compound of formula (V) in a protic solvent and add an acid, stir and react at room temperature to 60° C. for 2 to 30 hours, and remove the protecting group to obtain the compound of formula (I). The protic solvent used for this reaction is selected from water, alcohol or alcohol-water mixed solvent; the acid is selected from methanesulfonic acid, hydrochloric acid, trifluoroacetic acid.

3) When necessary, convert the obtained compound of formula (I) into its pharmaceutically acceptable salt or hydrate.

The compounds of formula (II) used as starting materials in the present invention are known compounds and can be easily prepared by methods known from prior publications. For example: J.Med.Chem.1991, 34, 1142; US4704459; US5457104 and so on.

The compound of formula (IV) used as a starting material in the present invention is a commonly used chemical reagent, which is commercially available in China.

According to the method shown in the following reaction scheme 2, another starting compound of the present invention, the compound of formula (III), can be prepared.

Reaction route 2:

In Reaction Scheme 2, R ₁ and R ₂ are as defined above.

The method shown in Reaction Scheme 2 is specifically explained below.

Selective catalytic hydrogenation of N-Boc-3-cyano-4-pyrrolidone (1) in the presence of Pd/C, followed by protection of the corresponding aminomethyl group with Boc to obtain compound 2, the latter in base (such as pyridine, triethylamine ) in the presence of condensation reaction with hydroxylamine hydrochloride to give pyrrolidine oximide 3 (R ₁ =H). On the other hand, 1 undergoes nucleophilic substitution reaction with methyl iodide to obtain methyl compound 4, and then sequentially undergoes selective catalytic hydrogenation and protects the aminomethyl group with Boc to obtain compound 5 and condensation reaction with hydroxylamine hydrochloride to obtain methylated oximate compound 3 (R ₁ =CH ₃ ). Substituent reaction of 3 with bromofluoromethane or Freon (difluorochloromethane) gives monofluoro/difluoromethoxyiminopyrrolidine 6, which is finally removed in the presence of acid (such as methanesulfonic acid, hydrochloric acid, trifluoroacetic acid) Two Boc protecting groups can obtain the compound of formula (III).

In Scheme 2, compound 1 used as a starting material is a known compound and can be easily prepared by methods known in prior publications. For example, Q.Guo et al., Eur.J.Med.Chem.2010, 45:5498; Wan Zhilong et al., Chinese Journal of Medicinal Chemistry 2009, 19:109.

The compound of the present invention with the R or S configuration can be resolved by conventional techniques in the art, or obtained by chiral synthesis using raw materials of the corresponding configuration.

The present invention also provides an antibacterial pharmaceutical composition containing the compound of formula (I) as defined above, or a pharmaceutically acceptable salt or hydrate thereof as an active ingredient.

The weight ratio of the naphthyridone carboxylic acid compound contained in the pharmaceutical composition is 0.1-99.9%, and the weight ratio of the pharmaceutically acceptable carrier in the composition is 0.1-99.9%. The pharmaceutical compositions are in the form of formulations suitable for pharmaceutical use. The pharmaceutical preparations are tablets, capsules, granules, pills, powders, ointments, suspensions, injections, powder injections, suppositories, creams, drops or patches. Wherein, the tablet is sugar-coated tablet, film-coated tablet, enteric-coated tablet or sustained-release tablet; the capsule is hard capsule, soft capsule, sustained-release capsule; the powder injection is Freeze-dried powder injection.

In the pharmaceutical composition of the present invention, as a preparation form, the effective amount of the compound of the invention contained in each dose is 0.1-1000 mg, and each dose refers to each preparation unit, such as each piece of a tablet, and each capsule of a capsule. , can also refer to each dosage, such as 100 mg each time.

When the pharmaceutical composition of the present invention is prepared into solid or semisolid pharmaceutical preparations in the form of powder, tablet, dispersible powder, capsule, cachet, suppository and ointment, a solid carrier can be used. The solid carrier that can be used is preferably one or more substances selected from diluents, flavoring agents, solubilizers, lubricants, suspending agents, binders, swelling agents, etc., or can be encapsulated substances. In powder formulations, the carrier contains from 5 to 70% of the micronized active ingredient. Suitable solid carriers include magnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin, dextrin, starch, gelatin, methylcellulose, sodium carboxymethylcellulose, a low boiling wax, cocoa butter, and the like. Because of their ease of administration, tablets, powders, cachets and capsules etc. represent the most advantageous oral solid preparations.

Liquid formulations of the invention include solutions, suspensions and emulsions. For example, injection preparations for parenteral administration may be in the form of water or water-propylene glycol solutions whose isotonicity, pH, etc. are adjusted to suit the physiological conditions of living bodies. Liquid preparations can also be prepared in solution in polyethylene glycol, aqueous solution. Oral aqueous solutions can be prepared by dissolving the active ingredient in water, and adding appropriate amount of coloring, flavoring, stabilizing and thickening agents. Aqueous suspensions suitable for oral administration can be prepared by dispersing the micronized active ingredient in viscous material, such as natural and synthetic gums, methylcellulose, sodium carboxymethylcellulose, and other known suspending agents.

It is especially advantageous to formulate the aforementioned pharmaceutical preparations in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form of formulation refers to physically discrete units suitable as unitary dosages, each unit containing a predetermined quantity of active ingredient calculated to produce the desired therapeutic effect. Such dosage unit form may be in packaged form, such as a tablet, capsule, or powder in a vial or vial, or as an ointment, gel, or cream in a tube or bottle.

Although the amount of active ingredient contained in dosage unit forms may vary, it will generally be adjusted within the range of 1 to 800 mg, depending on the potency of the active ingredient chosen.

When the active compound of formula (I) of the present invention is used as a drug for treating bacterial infection, it is preferred to administer 6-14 mg/kg body weight in the first stage. However, the dosage administered will vary with the needs of the patient, the severity of the infection to be treated, the compound selected, and the like.

Those skilled in the art can routinely determine the preferred dosage for a particular situation. Generally, the initial treatment dose is lower than the optimum dose of the active ingredient, and then the dose is gradually increased until the optimum therapeutic effect is achieved. The total daily dose may be administered in one or in divided doses as required for treatment.

As mentioned above, the compound of the present invention has unexpectedly strong antibacterial activity to important clinical pathogenic bacteria, and compared with the quinolone antibacterial drugs that have been listed, it has significantly more superior antibacterial activity, especially to including MRSA The in vitro activity of Staphylococcus aureus, Staphylococcus aeruginosa including MRSE, and Pseudomonas aeruginosa is 2->521 times that of the control drug ciprofloxacin, and 2-32 times that of gemifloxacin; against Staphylococcus aureus MRSA10- 2. The in vivo activities of Staphylococcus epidermis MRSE10-4 and Pseudomonas aeruginosa 10-1 are 1.4-6.1 times that of ciprofloxacin and gemifloxacin.

Detailed ways

The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Example 1 1-(N-Boc)-4-(N-Boc)aminomethyl-pyrrolidin-3-one

1-(N-Boc)-4-cyano-pyrrolidin-3-one (42.0 g, 0.2 mol) and (Boc) ₂ O (43.6 g, 0.2 mol) were dissolved in methanol (500 mL), to which was added 5% Pd/C (8.2g), stirred overnight at room temperature under 70 psi hydrogen pressure, filtered off Pd/C, concentrated the filtrate under reduced pressure, and purified the residue by column chromatography (gradient elution with petroleum ether and ethyl acetate). 31.5 g (yield: 50%) of light yellow oil was obtained. ¹ H NMR (DMSO-d ₆ , 400 MHz) δ _ppm : 6.98 (1H, s), 3.80-2.79 (7H, m), 1.42 (9H, s), 1.38 (9H, s). ESI-MS (m/z): 315 (M+H) ⁺ , 337 (M+Na) ⁺ .

Example 2 1-(N-Boc)-3-(N-Boc)aminomethyl-4-hydroxyiminopyrrolidine

At room temperature, add pyridine (40.2 mL, 0.5 mol) to a methanol solution of hydroxylamine hydrochloride (41.7 g, 0.6 mol), stir for 10 min, then add the compound of Example 1 (94.2 g, 0.3 mol), and stir for 1 h at the same temperature. It was concentrated under reduced pressure, and the residue was dissolved in ethyl acetate, washed successively with 10% glacial acetic acid, saturated aqueous sodium bicarbonate solution and water, and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure, petroleum ether (500 mL) was added thereto, heated to reflux, and left at room temperature, a large amount of solids precipitated out. After filtering, the filter cake was washed with petroleum ether and dried to obtain 80.0 g of white solid (yield: 80%), mp: 138-140°C. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ _ppm : 10.91 (1H, s), 6.94 (1H, s), 3.92-3.85 (2H, m), 3.54-3.48 (1H, m), 3.32-3.12 ( 2H, m), 3.00-3.90 (2H, m), 1.44 (18H, s). MS-ESI (m/z): 330 (M+H) ⁺ .

Example 3 1-(N-Boc)-4-methyl-4-cyanopyrrolidin-3-one

Add 1-(N-Boc)-4-cyano-pyrrolidin-3-one (21.0g, 0.1mol) and anhydrous potassium carbonate (41.7g, 0.3mol) to a solution of anhydrous acetone (800mL) at room temperature Add iodomethane (8.2 mL, 0.12 mol) dropwise to the mixture, and stir at the same temperature for 3 h after the drop (30 min). Filtrate, concentrate the filtrate under reduced pressure, add dichloromethane (200 mL) to dissolve, wash with water (200 mL×3), and concentrate under reduced pressure. Add petroleum ether (300mL) to the residue, heat to reflux for 1h, filter, wash the filter cake with an appropriate amount of petroleum ether, and recrystallize with a mixed solvent of petroleum ether and ethyl acetate to obtain 18.8g of off-white solid (yield: 84 %), mp: 71-73°C. ¹ H NMR (CDCl ₃ , 400 MHz) δ _ppm : 4.15-3.69 (4H, m), 1.58 (3H, s), 1.49 (9H, s). ESI-MS (m/z): 225 (M+H) ⁺ .

Example 4 1-(N-Boc)-4-methyl-4-(N-Boc)aminomethylpyrrolidin-3-one

Dissolve the compound of Example 3 (11.2g, 50mmol) and (Boc) ₂ O (10.9g, 50mmol) in methanol (200mL), add Pd/C (5%, 2.0g), stir overnight at room temperature under 75psi hydrogen pressure . Pd/C was filtered off, the filtrate was concentrated under reduced pressure, petroleum ether (500 mL) was added to the residue, and the mixture was heated to reflux for 30 min. Filtrate while hot, wash the filter cake with petroleum ether, and recrystallize with a mixed solvent of petroleum ether and ethyl acetate to obtain 12.8 g of off-white solid (yield: 78%), mp: 106-108 ° C. ¹ H NMR ( CDCl ₃ , 400MHz) δ _ppm : 4.77 (1H, brs), 3.83 (2H, s), 3.64-3.26 (4H, m), 1.50 (9H, s), 1.43 (9H, s), 1.15 (3H, s ). ESI-MS (m/z): 329 (M+H) ⁺ .

Example 5 1-(N-Boc)-3-methyl-3-(N-Boc)aminomethyl-4-hydroxyiminopyrrolidine

Under stirring at room temperature, pyridine (2.4 mL, 30 mmol) was added to a solution of hydroxylamine hydrochloride (2.5 g, 36 mmol) in methanol (100 mL), and stirred for 10 min. To this solution was added dropwise the compound of Example 4 (9.8 g, 30 mmol) in methanol (50 mL), and after 10 min, the solution was stirred at the same temperature for 1 h. Concentrate under reduced pressure, add dichloromethane to the residue to dissolve (100 mL), wash with water, and dry over anhydrous sodium sulfate. Filtrate, concentrate the filtrate under reduced pressure, add petroleum ether (300mL) to the residue, heat to reflux for 1h, filter while hot, wash the filter cake with ethyl acetate and petroleum ether, and dry to obtain 9.5g of off-white solid (yield: 93%) , mp: 149-150°C. ¹ H NMR (CDCl ₃ , 400MHz) δ _ppm : 10.86 (1H, brs), 6.94 (1H, brs), 3.96 (2H, s), 3.50-2.98 (4H, m), 1.40 (9H, s), 1.36 (9H, s), 1.06 (3H, s). ESI-MS (m/z): 344 (M+H) ⁺ , 366 (M+Na) ⁺ .

Example 6 1-(N-Boc)-3-methyl-3-(N-Boc)aminomethyl-4-fluoromethoxyiminopyrrolidine

Under stirring at room temperature, to the toluene (100mL) solution of the compound of Example 5 (3.4g, 10mmol) and tetrabutylammonium bromide (0.6g, 2mmol), add 50% NaOH aqueous solution of 8 times molar amount, stir to reaction mixture Fluorobromomethane (1.2 g, 11 mmol) was passed into the mixture, and stirred at the same temperature for 5 hours. The organic layer was separated, washed with water, and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure to obtain 3.8 g (quantitative) of a colorless oil. ¹ H NMR (CDCl ₃ , 400MHz) δ _ppm : 7.08 (1H, br s), 5.66 (2H, t, J=56.0Hz), 4.09 (2H, s), 3.53-2.97 (4H, m), 1.40 ( 9H, s), 1.36 (9H, s), 1.09 (3H, s). ESI-MS (m/z): 376 (M+H) ⁺ .

Example 7 1-(N-Boc)-3-(N-Boc)aminomethyl-4-fluoromethoxyiminopyrrolidine

Same as the preparation method of the compound of Example 6, the compound of Example 2 was reacted with bromofluoromethane to obtain a colorless oil (quantitative). ¹ H NMR (400MHz, DMSO-d ₆ ) δ _ppm : 7.07 (1H, br s), 5.68 (2H, d, J=56Hz), 4.05 (2H, brs), 3.57 (1H, brs), 3.31-3.27 (1H, m), 3.19 (1H, brs), 3.10-3.03 (2H, m), 1.45 (9H, s), 1.40 (9H, s). MS-ESI (m/z): 362.2 (M+H) ⁺ .

Example 8 1-(N-Boc)-3-(N-Boc)aminomethyl-4-difluoromethoxyiminopyrrolidine

Under stirring at room temperature, to the toluene (150mL) solution of the compound of Example 2 (6.6g, 20mmol) and tetrabutylammonium bromide (1.2g, 4mmol), add 50% NaOH aqueous solution of 8 times molar amount, stir to reaction mixture Freon (F2CHCl) gas was introduced into the mixture, and stirred at 80°C for 10 hours. The organic layer was separated, washed with water, and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure, and silica gel column chromatography gave 2.27 g of a colorless oil (yield: 30%). ¹ H NMR (400 MHz, DMSO-d ₆ ) δ _ppm : 7.07 (1H, brs), 7.06 (1H, t, J=72Hz), 4.09 (2H, brs), 3.58 (1H, brs), 3.32-3.28 ( 1H, m), 3.20 (1H, brs), 3.11-3.07 (2H, m), 1.41 (9H, s), 1.37 (9H, s). MS-ESI (m/z): 380.4 (M+H) ⁺ .

Example 9 3-aminomethyl-4-fluoromethoxyimino-pyrrolidine dimesylate

Under stirring at room temperature, methanesulfonic acid (5.76 g, 60 mmol) was added to a solution of the compound of Example 7 (7.2 g, 20 mmol) in methanol (50 mL), and stirred at the same temperature for 24 h. The precipitated solid was filtered and dried in vacuo to obtain 4.94 g (yield: 70%) of a white solid, mp: 137-139°C. ¹ H NMR (400MHz, DMSO-d ₆ ) δ _ppm : 9.32 (2H, brs), 7.99 (3H, brs), 5.74 (2H, d, J=56Hz), 4.16-3.99 (2H, m), 3.75- 3.71 (1H, m), 3.36-3.28 (2H, m), 3.19-3.07 (2H, m), 2.38 (6H, s). MS-ESI (m/z): 162.1 (M+H) ⁺ .

3-Methyl-4-fluoromethoxyiminopyrrolidine dimesylate (0.36g, 1mmol) in absolute anhydrous methanol (6mL) solution, under full stirring, add 2 times the molar amount of sodium hydroxide (0.08g, 2mmol), and continued stirring at the same temperature for 0.5 hours. Concentrate under reduced pressure, and the residue is separated and purified by column chromatography to obtain 0.33 g of 3-methyl-4-fluoromethoxyiminopyrrolidine (yield: 95%).

Salts such as:

3-Methyl-4-fluoromethoxyimino-pyrrolidine dihydrochloride;

3-Methyl-4-fluoromethoxyimino-pyrrolidine bis(trifluoro)acetate.

Example 10 3-aminomethyl-4-difluoromethoxyiminopyrrolidine dimesylate

The same as the preparation method of the compound of Example 9, the compound of Example 8 was reacted with methanesulfonic acid to obtain a white solid (yield: 90%), mp: 168-170°C. ¹ H NMR (400MHz, DMSO-d ₆ ) δ _ppm : 9.35 (2H, brs), 7.97 (3H, brs), 7.16 (1H, t, J=72Hz), 4.22-4.05 (2H, m), 3.77- 3.73 (2H, m), 3.45-3.40 (1H, m), 3.16-3.12 (2H, m), 2.37 (6H, s). MS-ESI (m/z): 180.2 (M+H) ⁺ .

Example 11 3-methyl-3-aminomethyl-4-fluoromethoxyiminopyrrolidine dimesylate

Similar to the preparation method of the compound of Example 9, the compound of Example 6 was reacted with methanesulfonic acid to obtain a white solid (yield: 86%). ¹ H NMR (400MHz, DMSO-d ₆ ) δ _ppm : 9.32 (2H, brs), 7.58 (3H, brs), 5.70 (2H, t, J=56.0Hz), 4.09 (2H, s), 3.77-3.05 (4H, m), 2.37 (6H, s), 1.09 (3H, s). MS-ESI (m/z): 176.2 (M+H) ⁺ .

Example 12 1-cyclopropyl-6-fluoro-7-[3-benzylideneaminomethyl-4-(a fluoromethoxyimino)-pyrrolidin-1-yl]-1,4- Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid

Under nitrogen protection and stirring at room temperature, dry triethylamine (115mL, 0.8mol) and benzaldehyde (12mL, 0.12mol) were added to the suspension of the compound of Example 9 (35.34g, 0.1mol) in anhydrous acetonitrile (500mL). ), and stirred at the same temperature for 1 h. Add 1-cyclopropyl-6-fluoro-7-chloro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid (25g, 0.09mol) to it, and continue at the same temperature Stir overnight. The precipitated solid was filtered and washed with acetonitrile to obtain 39.6 g (yield: 80%) of a white solid, mp: 176-178°C. ¹ H NMR (400MHz, DMSO-d ₆ ) δ _ppm : 15.22 (1H, s), 8.53 (1H, s), 8.38 (1H, s), 7.91 (1H, d, J=13Hz), 7.58 (2H, d, J=8Hz), 7.36-7.27(3H, m), 5.77(2H, d, J=56Hz), 4.71-4.62(2H, m), 4.13-4.09(2H, m), 3.93-3.85(2H , m), 3.67-3.62 (1H, m), 3.52-3.49 (1H, m), 1.13-0.99 (4H, m). MS-FAB (m/z): 496.9 (M+H) ⁺ .

Compounds such as:

1-cyclopropyl-6-fluoro-7-[3-p-nitrobenzylidene aminomethyl-4-(a fluoromethoxyimino)-pyrrolidin-1-yl]-1,4- Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid

1-cyclopropyl-6-fluoro-7-[3-ethylideneaminomethyl-4-(fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4 -Oxo-1,8-naphthyridine-3-carboxylic acid

Example 13 1-cyclopropyl-7-[3-benzylidene aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4 -Oxo-1,8-naphthyridine-3-carboxylic acid

With the preparation method of the compound of Example 12, the compound of Example 9 reacts with 1-cyclopropyl-7-chloro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid to obtain white Solid (yield: 76%). ¹ H NMR (400MHz, DMSO-d ₆ ) δ _ppm : 15.20 (1H, s), 8.54 (1H, s), 8.36 (1H, s), 7.65-7.59 (2H, m), 7.54 (2H, d, J=8Hz), 7.36-7.27(3H, m), 5.77(2H, d, J=56Hz), 4.70-4.65(2H, m), 4.12-4.09(2H, m), 3.93-3.85(2H, m ), 3.67-3.63 (1H, m), 3.48-3.43 (1H, m), 1.13-0.99 (4H, m). MS-FAB (m/z): 478.25 (M+H) ⁺ .

Example 14 1-(2,4-difluorophenyl)-6-fluoro-7-[3-benzylidene aminomethyl-4-(one fluoromethoxyimino)-pyrrolidine-1- base]-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid

With the preparation method of the compound of Example 12, the compound of Example 9 and 1-(2,4-difluorophenyl)-6-fluoro-7-chloro-1,4-dihydro-4-oxo-1,8 -Naphthyridine-3-carboxylic acid was reacted to give a white solid (yield: 70%) mp: 248-250°C. ¹ H NMR (400MHz, CDCl ₃ ) δ _ppm : 14.74 (1H, s), 8.64 (1H, s), 8.27 (1H, s), 8.08 (1H, d, J=13Hz), 7.66-7.52 (2H, m), 7.43-7.32 (4H, m), 7.03-6.99 (2H, m), 5.61 (2H, d, J=56Hz), 4.46-3.36 (7H, m). MS-ESI (m/z): 568.4 (M+H) ⁺ .

Example 15 1-cyclopropyl-6-fluoro-7-[3-benzylideneaminomethyl-4-(difluoromethoxyimino)-pyrrolidin-1-yl]-1,4- Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid

With the preparation method of the compound of Example 12, the compound of Example 10 and 1-cyclopropyl-6-fluoro-7-chloro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxyl The acid reaction gave a white solid (yield: 76%), mp: 205-207°C. ¹ H NMR (400MHz, DMSO-d ₆ ) δ _ppm : 15.19 (1H, br s), 8.55 (1H, s), 8.39 (1H, s), 7.94 (1H, d, J=13Hz), 7.58 (2H , d, J=8Hz), 7.36-7.27 (3H, m), 7.16 (1H, t, J=72Hz), 4.77-4.70 (2H, m), 4.20-4.13 (2H, m), 3.91-3.89 ( 2H, m), 3.68-3.62 (1H, m), 3.59-3.56 (1H, m), 1.14-1.00 (4H, m). MS-FAB (m/z): 514.2 (M+H) ⁺ .

Example 16 1-(2,4-difluorophenyl)-6-fluoro-7-[3-benzylideneaminomethyl-4-(difluoromethoxyimino)-pyrrolidine-1- base]-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid

With the preparation method of the compound of Example 12, the compound of Example 10 and 1-(2,4-difluorophenyl)-6-fluoro-7-chloro-1,4-dihydro-4-oxo-1,8 -Naphthyridine-3-carboxylic acid was reacted to give a white solid (yield: 70%). ¹ H NMR (400MHz, CDCl ₃ ) δ _ppm : 14.96 (1H, s), 8.88 (1H, s), 8.19 (1H, d, J=13Hz), 7.92-7.78 (4H, m), 7.58 (3H, m), 7.36-7.27(4H, m), 7.14(1H, t, J=72Hz), 4.46-4.00(3H, m), 3.92-3.60(1H, m), 3.53-3.40(1H, m), 3.18-3.03 (2H, m), 2.29 (3H, s). MS-FAB (m/z): 586.2 (M+H) ⁺ .

Example 17 1-cyclopropyl-6-fluoro-7-[3-methyl-3-benzylidene aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl] -1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid

With the preparation method of the compound of Example 12, the compound of Example 11 and 1-cyclopropyl-6-fluoro-7-chloro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxyl The acid reacted to give an off-white solid (yield: 75%). ¹ H NMR (400MHz, CDCl ₃ ) δ _ppm : 8.58 (1H, s), 8.03 (1H, d, J=12.8Hz), 7.58 (2H, m), 7.36-7.27 (3H, m), 5.76 (2H , d, J=64Hz), 4.71(2H, s), 4.28(1H, d, J=11.2Hz), 3.75-3.71(2H, m), 3.31(2H, s), 2.73(2H, q, J = 12.8 Hz), 1.25 (3H, s), 1.22-1.17 (2H, m), 1.12-1.09 (2H, m). MS-FAB (m/z): 510.2 (M+H) ⁺ .

Example 18 1-cyclopropyl-7-[3-methyl-3-benzylidene aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4 -Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid

With the preparation method of Example 12 compound, Example 11 compound reacts with 1-cyclopropyl-7-chloro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid to obtain White solid (yield: 78%). ¹ H NMR (400MHz, CDCl ₃ ) δ _ppm : 8.58 (1H, s), 7.36-7.27 (3H, m), 7.36-7.58 (4H, m), 7.36-7.27 (3H, m), 5.76 (2H, d, J=64Hz), 4.71(2H, s), 4.28(1H, d, J=11.2Hz), 3.75-3.71(2H, m), 3.31(2H, s), 2.73(2H, q, J= 12.8Hz), 1.25 (3H, s), 1.22-1.17 (2H, m), 1.12-1.09 (2H, m). MS-FAB (m/z): 492.2 (M+H) ⁺ .

Example 19 1-cyclopropyl-6-fluoro-7-[3-aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4 -Oxo-1,8-naphthyridine-3-carboxylic acid methanesulfonate

Under stirring at room temperature, methanesulfonic acid (5.76 g, 60 mmol) and water (5 mL) were added to the ethanol (500 mL) solution of the compound of Example 12 (29.7 g, 60 mmol), and stirred at the same temperature for 24 h. The precipitated solid was filtered and dried in vacuo to obtain 19.6 g of white solid (yield: 80%), mp: 220-222°C. ¹ H NMR (400MHz, DMSO-d ₆ ) δ _ppm : 15.22 (1H, brs), 8.60 (1H, s), 8.08 (1H, d, J=13Hz), 7.95 (3H, brs), 5.79 (2H, d, J=56Hz), 4.71-4.64 (2H, m), 4.44-4.39 (1H, m), 3.88-3.83 (1H, m), 3.74-3.68 (1H, m), 3.52-3.49 (1H, m ), 3.20-3.14 (2H, m), 2.31 (3H, s), 1.24-1.02 (4H, m). MS-FAB (m/z): 408.4 ₍ M+H ₎ ⁺ _. HRMS- _FAB : m/z Calcd. for _C18H20N5O4F2 (M+H) ⁺ : 408.1483.

Example 20 1-cyclopropyl-7-[3-aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4-oxo- 1,8-Naphthyridine-3-carboxylic acid methanesulfonate

With the preparation method of the compound of Example 19, the compound of Example 13 reacts with 1-cyclopropyl-7-chloro-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid to obtain white Solid (yield: 58%), mp: >240°C. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ _ppm : 15.43 (1H, s), 8.59 (1H, s), 8.34 (1H, brs), 7.95 (3H, brs), 6.93 (1H, brs), 5.80 (2H, d, J=56Hz), 4.61-4.40 (2H, m), 4.29-4.00 (1H, m), 3.80-3.08 (5H, m), 2.31 (3H, s), 1.22-1.06 (4H, m). MS-ESI (m/z): 390.2 (M+H) ⁺ .

Example 21 1-(2,4-difluorophenyl)-6-fluoro-7-[3-aminomethyl-4-(one-fluoromethoxyimino)-pyrrolidin-1-yl]-1 , 4-Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid methanesulfonate

The same preparation method as Example 19 compound, Example 14 reacted with methanesulfonic acid to obtain a white solid (yield: 68%), mp: 168-170°C. ¹ H NMR (400 MHz, DMSO-d ₆ ) δ _ppm : 8.84 (1H, s), 8.17 (1H, d, J=13Hz), 7.86-7.78 (4H, m), 7.59-7.56 (1H, m), 7.36-7.32(1H, m), 5.72(2H, d, J=56Hz), 4.46-3.90(3H, m), 3.72-3.30(2H, m), 3.20-3.00(2H, m), 2.32(3H , s). MS-FAB (m/z): 480.1 (M+H) ⁺ . HRMS _{-FAB: m/z Calcd. for C21H18N5O4F4 ( M +} H) ₊ ^: 480.1295.

Example 22 1-cyclopropyl-6-fluoro-7-[3-aminomethyl-4-(difluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4 -Oxo-1,8-naphthyridine-3-carboxylic acid methanesulfonate

Similar to the preparation method of the compound of Example 19, the compound of Example 15 was reacted with methanesulfonic acid to obtain a white solid (yield: 65%). mp: 235-237°C. ¹ H NMR (400MHz, DMSO-d ₆ ) δ _ppm : 15.19 (1H, brs), 8.59 (1H, s), 8.08 (1H, d, J=13Hz), 8.00 (3H, brs), 7.18 (1H, t, J=72Hz), 4.77-4.66 (2H, m), 4.46-4.41 (1H, m), 3.91-3.87 (1H, m), 3.74-3.68 (1H, m), 3.61-3.53 (1H, m ), 3.45-3.41 (1H, m), 3.22-3.20 (1H, m), 2.32 (3H, s), 1.24-1.02 (4H, m). MS-FAB (m/z): 426.1 (M+H) ⁺ . HRMS- _{ESI: m/z Calcd. for C18H19N5O4F3 ( M} +H) ₊ ^: 426.1404 _.

Example 23 1-(2,4-difluorophenyl)-6-fluoro-7-[3-aminomethyl-4-(difluoromethoxyimino)-pyrrolidin-1-yl]-1 , 4-Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid methanesulfonate

Similar to the preparation method of the compound of Example 19, the compound of Example 16 was reacted with methanesulfonic acid to obtain a white solid (yield: 50%). mp: 145-147°C. ¹ H NMR (400MHz, DMSO-d ₆ ) δ _ppm : 14.96 (1H, s), 8.88 (1H, s), 8.19 (1H, d, J=13Hz), 7.92-7.78 (4H, m), 7.58- 7.51(1H, m), 7.36-7.32(1H, m), 7.10(1H, t, J=72Hz), 4.46-4.00(3H, m), 3.92-3.60(1H, m), 3.53-3.40(1H , m), 3.18-3.03 (2H, m), 2.29 (3H, s). MS-FAB (m/z): 498.0 (M+H) ⁺ . HRMS- _FAB : m _{/z Calcd. for C21H17N5O4F5 ( M} +H) ⁺ : 498.1201 _.

Example 24 1-cyclopropyl-6-fluoro-7-[3-methyl-3-aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4 -Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid

The preparation method of the compound of Example 19 was the same. After the reaction of the compound of Example 17 (0.51 g, 1 mmol) with methanesulfonic acid was completed, the pH=7 was adjusted with 1N sodium hydroxide solution, evaporated to dryness under reduced pressure, and the residue was passed through a silica gel column (with Dichloromethane and methanol (gradient elution) were separated to obtain 0.41 g of white solid (yield: 97.6%), mp: 195°C. ¹ H NMR (DMSO-d ₆ , 400MHz) δ _ppm : 8.58 (1H, s), 8.03 (1H, d, J = 12.8Hz), 5.76 (2H, d, J = 64Hz), 4.71 (2H, s) , 4.28(1H, d, J=11.2Hz), 3.75-3.71(2H, m), 3.31(2H, s), 2.73(2H, q, J=12.8Hz), 1.25(3H, s), 1.22- 1.17 (2H, m), 1.12-1.09 (2H, m). ESI-MS (m/z): 422 (M+H) ⁺ . _HRMS - _ESI (m/z): _C19H22F2N5O4 , Calcd: _422.1640 ; _Found 422.1656.

C ₁₉ H ₂₁ F ₂ N ₅ O ₄ C h N F Calculated 54.15 5.02 16.62 9.02 measured value 54.18 5.00 16.60 8.99

Example 25 1-cyclopropyl-6-fluoro-7-[3-methyl-3-aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4 -Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid monohydrate

The compound of Example 24 (0.42 g, 1 mmol) was dissolved in 5% acetic acid (8 mL). With stirring at room temperature, the pH was adjusted to 7 with 1N sodium hydroxide solution, and a solid precipitated upon standing. Filtration and drying gave 1-cyclopropyl-6-fluoro-7-[3-methyl-3-aminomethyl-4-(one-fluoromethoxyimino)-pyrrolidin-1-yl]-1 , 0.35 g of 4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid monohydrate (off-white solid, yield: 80%).

C ₁₉ H ₂₁ F ₂ ^N ₅ O ₄ H ₂ O C h N F Calculated 51.93 5.28 15.94 8.65 measured value 51.90 5.29 15.93 8.67

Example 26 1-cyclopropyl-6-fluoro-7-[3-methyl-3-aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4 -Dihydro-4-oxo-1,8-naphthyridine-3-carboxylate hydrochloride

Under reflux and stirring, 1.5 times the molar amount of 6N hydrochloric acid (dissolved) was added to the absolute ethanol suspension (20mL) of the compound of Example 24 (0.42g, 1mmol), and the stirring was continued for 0.5 hours, cooled to room temperature, and precipitated solid. Filtration and drying gave 1-cyclopropyl-6-fluoro-7-[3-methyl-3-aminomethyl-4-(one-fluoromethoxyimino)-pyrrolidin-1-yl]-1 , 0.42 g of 4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid hydrochloride (off-white solid, yield: 92%).

C ₂₆ H ₂₈ FN ₅ O ₆ ^HCl C h N F Cl Calculated 55.57 5.20 12.46 3.38 6.31 measured value 55.62 5.21 12.37 3.39 6.30

Salts such as:

1-cyclopropyl-6-fluoro-7-[3-methyl-3-aminomethyl-4-(fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro - 4-oxo-1,8-naphthyridine-3-carboxylic acid lactate;

1-cyclopropyl-6-fluoro-7-[3-methyl-3-aminomethyl-4-(fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro -4-Oxo-1,8-naphthyridine-3-carboxylic acid p-toluenesulfonate.

Example 27 1-cyclopropyl-7-[3-methyl-3-aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro- 4-oxo-1,8-naphthyridine-3-carboxylic acid

Similar to the preparation method of the compound of Example 24, a white solid can be obtained from the compound of Example 18 (yield: 100%), mp: 184-186°C. ¹ H NMR (DMSO-d ₆ , 400MHz) δ _ppm : 8.57 (1H, s), 8.29 (1H, s), 6.94 (1H, s), 5.76 (2H, d, J=65.6Hz), 4.53 (2H , s), 4.14-4.02(1H, m), 3.77-3.71(1H, m), 3.58-3.31(1H, m), 2.70(2H, q), 1.25(3H, s), 1.20-1.12(2H , m), 1.09-1.03 (2H, m). ESI-MS (m/z): 404 (M+H) ⁺ . HRMS _- ESI (m/z): _C19H23FN5O4 , _Calcd : _404.1734 ; Found 404.1739.

Example 28

coated tablet

Tablet prescription:

Take the above ingredients and mix evenly, granulate, sieve and adjust the granules, dry and tablet to make 100 tablet cores.

Coating Solution Prescription:

Opadry (Opadry) 5g, 80% ethanol appropriate amount of coating.

Example 29 Capsules

prescription:

Preparation:

Take the prescription amount of raw and auxiliary materials, sieve them separately, add 5% polyvinylpyrrolidone alcohol solution and Tween 80 soft material, granulate with a 20-mesh sieve, dry at room temperature at 15°C, add sodium lauryl sulfate, mix Evenly, according to 0.27g/S, put into No. 0 stomach-soluble capsules, take a sample for testing, the dissolution limit is Q=80%, and the content should be 90-110% of the labeled amount.

Example 30 Preparation of Injection

Take 1 gram of the compound of Example 27, add appropriate amount of water for injection to dissolve, add 10 grams of poloxamer, add 4 grams of sodium chloride, 10 grams of dextran, add 4 grams of glucose, 5 grams of mannitol, mix well, add Water for injection to 1000 ml, made into 10 bottles of intravenous injection.

Experimental example 1

This experimental example is to study the in vitro antibacterial activity of the compound of the present invention.

The antibacterial activity of the compound of the present invention is realized by measuring its minimum inhibitory concentration (MIC, mg/L) to standard strains and clinical isolates. The minimum inhibitory concentration was determined by the following method: use plate double dilution method and Denlay multi-point inoculator to carry out drug susceptibility test, the experimental bacteria are enriched with nutrient broth and annoyed infusion; after the drug is dissolved, it is double diluted with MH broth After the MH agar medium is melted, it is quantitatively injected into the plate containing the drug solution and mixed evenly. The final concentrations of the drug are 0.008, 0.015, 0.03, 0.06, 0.125..... .128μg/mL, inoculate the experimental bacteria (10 ⁵ cfu/point) with a multi-point inoculator after the medium in the plate is solidified, and incubate at a constant temperature of 35°C for 18 hours to observe the results. The minimum concentration of the drug contained in the sterile growth plate That is the minimum inhibitory concentration (MIC).

Table 1 has listed the in vitro antibacterial activity of some representative compounds in the formula (I) compound of the application to some important clinical pathogenic bacterial strains, and with the excellent fluoroquinolone antibacterial drug ciprofloxacin widely used clinically at present and recent Newly listed gemifloxacin for comparison.

Table 1 Embodiment 21 and 23 compounds are to the in vitro antibacterial activity of Gram-positive bacteria

As can be seen from Table 1, the compound of embodiment 21 and the compound of embodiment 23 in the compound of formula (I) of the present application are active to Staphylococcus aureus including MRSA, Staphylococcus aureus including MRSE and Pseudomonas aeruginosa It is 2->521 times of ciprofloxacin and 2-32 times of gemifloxacin.

Experimental example 2

This experimental example is to study the in vivo antibacterial activity of the compound of the present invention.

The test drugs were all prepared with 0.9% normal saline, the dose group interval was 1:0.65-1:0.8, and each compound had 5 dose groups.

Take healthy Kunming mice, with a body weight of 18-22 g, and randomly divide them into groups according to sex and body weight. There are 10 mice in each group, half male and half male, respectively. mL. After infection, give the mice oral gavage and intravenous injection containing different concentrations of the compound to be tested, each time 0.5mL, 4 hours after oral administration, and then gavage once again. At the same time, an infection control group was set up, and the infection control group was recorded. The number of mice died within 7 days afterward. The experimental results were calculated using the Bliss method in the DAS 110 software to calculate the half effective dose ED ₅₀ and 95% confidence limit, and carried out statistical processing.

Table 2 embodiment 19 and 20 compound and control drug are to the in vivo curative effect (ED ₅₀ mg/kg) of mouse abdominal cavity infection pathogenic bacteria

As can be seen from Table 2, when embodiment 19 and 20 compounds are orally gavaged, the curative effect in the body of Staphylococcus aureus MRSA10-2, Staphylococcus aeruginosa MRSE10-4 and Pseudomonas aeruginosa 10-1 is better than that of contrast drug gemifloxacin and 1.4-6.1 times that of ciprofloxacin.

In terms of pharmacokinetic properties, compared with known fluoroquinolone compounds, the compound of the present invention has suitable water solubility, so it can be well absorbed in the body, exhibits very high bioavailability, and is suitable for use as an antibacterial agent.

Experimental example 3

This experimental example is to study the oral acute toxicity of the compound of the present invention.

In order to measure the oral acute toxicity of the compound of the present invention, the compound of Example 22 and the compound of Example 24 were subjected to an acute toxicity test, and the solutions containing these two compounds of different concentrations were orally given to male mice at a dose of 0.1ml/10g After 7 days, the body weight of the dead mice was counted, and the median lethal dose (LD ₅₀ ) of each compound was calculated using the Bliss program. The results are listed in Table 3.

Table 5 Mice oral acute toxicity of experimental compounds

experimental compound _LD50 (mg/kg) Example 22 ＞3000 Example 24 ＞3000

Experimental results show that these compounds have very low toxicity and are very suitable for medicinal use.

Although the present invention has been described in detail with general descriptions and specific embodiments above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the protection scope of the present invention.

Claims (10)

1. Compounds represented by formula (I) or pharmaceutically acceptable salts and hydrates thereof:

in: R represents cyclopropyl, 2,4-difluorophenyl; R ₁ represents H, CH ₃ ; R ₂ represents CH ₂ F, CHF ₂ ; X stands for H and F. 2. the compound shown in formula (I) according to claim 1 or its medicinal salt, hydrate, it is characterized in that, described compound is selected from: 1-cyclopropyl-6-fluoro-7-[3-aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl)]-1,4-dihydro-4-oxo Dai-1,8-naphthyridine-3-carboxylic acid 1-cyclopropyl-6-fluoro-7-[3-aminomethyl-4-(difluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4-oxo -1,8-Naphthyridine-3-carboxylic acid 1-cyclopropyl-7-[3-aminomethyl-4-(one-fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4-oxo-1,8 -Naphthyridine-3-carboxylic acid 1-(2,4-difluorophenyl)-6-fluoro-7-[3-aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4- Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid 1-(2,4-difluorophenyl)-6-fluoro-7-[3-aminomethyl-4-(difluoromethoxyimino)-pyrrolidin-1-yl]-1,4- Dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acid 1-cyclopropyl-6-fluoro-7-[3-methyl-3-aminomethyl-4-(fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro -4-oxo-1,8-naphthyridine-3-carboxylic acid 1-cyclopropyl-7-[3-methyl-3-aminomethyl-4-(one fluoromethoxyimino)-pyrrolidin-1-yl]-1,4-dihydro-4-oxo Generation-1,8-naphthyridine-3-carboxylic acid. 3. The compound according to any one of claims 1 or 2 or its pharmaceutically acceptable salt or hydrate, wherein the pharmaceutically acceptable salt is a salt formed with an inorganic acid or an organic acid. 4. A pharmaceutical composition containing any one compound of claim 1 or 2 or a pharmaceutically acceptable salt or hydrate thereof. 5. The pharmaceutical composition according to claim 4, characterized in that, the composition is tablet, capsule, granule, pill, powder, ointment, suspension, injection, powder injection, suppository, cream, drops or patch. 6. The pharmaceutical composition according to claim 5, wherein the tablet is a sugar-coated tablet, a film-coated tablet, an enteric-coated tablet or a sustained-release tablet; the capsule is a hard capsule , soft capsules, sustained-release capsules; the powder injection is freeze-dried powder injection. 7. The intermediate for preparing the compound of claim 1 or its pharmaceutically acceptable salt or hydrate, characterized in that it is a compound shown in formula (III) or its salt formed with hydrochloric acid, methanesulfonic acid, trifluoroacetic acid

Wherein, R ₁ and R ₂ are as defined in claim 1. 8. A preparation method of the compound according to claim 1 or a pharmaceutically acceptable salt thereof, hydrate, characterized in that, comprising the steps of: 1) Add a base to an aprotic dipolar solvent, and conduct a condensation reaction between the compound of formula (II), the compound of formula (III) and the compound of formula (IV) at room temperature to 100° C. for 0.5 to 10 hours to obtain the compound of formula (V). 2) Then place the compound of formula (V) in a protic solvent and add an acid, stir and react at room temperature to 60° C. for 2 to 30 hours, and remove the protecting group to obtain the compound of formula (I).

in: The definitions of R, R ₁ , R ₂ and X are the same as in claim 1; R ₃ represents an alkyl or aryl group. 9. preparation method according to claim 8 is characterized in that, described aprotic dipolar solvent is selected from N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl methylene sulfone or acetonitrile; the base is selected from triethylamine, sodium carbonate, sodium bicarbonate, potassium carbonate, sodium hydroxide or potassium hydroxide; the protic solvent is selected from water, alcohol or alcohol-water mixed solvent; the The acid is selected from methanesulfonic acid, hydrochloric acid, trifluoroacetic acid. 10. The compound represented by formula (I) or a pharmaceutically acceptable salt or hydrate thereof according to claim 1, characterized in that it is in R or S configuration.