CN1429813A - Synthetic method of 1,5-methyl naphtualene diamino formate - Google Patents

Abstract

A method for synthesizing methyl 1,5-naphthalene dicarbamate. The main technical feature is that 1,5-diaminonaphthalene reacts with dimethyl carbonate in a solvent to catalyze the synthesis of methyl 1,5-naphthalene dicarbamate. The reaction mixture was taken out to cool down and separated to obtain solid methyl 1,5-naphthalene dicarbamate. Its advantage is to use "green chemical" dimethyl carbonate (DMC) as raw material, which can realize simple, safe, and pollution-free clean production; the reaction only produces methanol by-product, and methanol is the raw material for synthesizing DMC. Combining methanol and CO , O ₂ oxidative carbonylation process to synthesize DMC, which can achieve "zero discharge" in the chemical process and realize atomic economy; the reaction conditions are mild, easy to operate, the catalyst used is cheap, and the product yield is high, up to 95%.

Description

1, the synthetic method of methyl 5-naphthalene dicarbamate

Technical Field of the Invention

The invention belongs to a chemical synthesis method, in particular to a catalytic synthesis of 1,5-diaminonaphthalene (also known as 1,5-naphthalene diamine, referred to as NDA) and dimethyl carbonate (abbreviated as DMC). -Naphthalene dicarbamate (abbreviated as NDC) method.

Background Art of the Invention

Methyl 1,5-naphthalene dicarbamate (NDC) is an intermediate for the synthesis of 1,5-naphthalene diisocyanate (NDI for short). NDI is the raw material for synthesizing advanced polyurethane. Its products have high melting point, high strength, good resilience, excellent dynamic performance, heat resistance, wear resistance, oil resistance and long service life. It can be used in the workplace where ordinary polyurethane cannot meet the requirements or premature damage , the application prospect is broad.

At present, the production of 1,5-naphthalene diisocyanate (NDI) adopts the phosgene method. The phosgene method needs to use highly toxic phosgene and liquid phosgene as raw materials, the operating environment is harsh, the reaction conditions are harsh, the pollution is serious, the process is long, and the technology is complicated; a large amount of hydrochloric acid is produced in the synthesis, which corrodes the equipment; residual chlorine in the product Difficult to remove and difficult to refine.

US4330479, EP396976, JP344730, Chem Commun, 1998, (23): 2575-2576 documents disclose a kind of 1,5-naphthalene dicarbamate cracking synthetic 1, the method of 5-naphthalene diisocyanate (NDI), is The only way to develop 1,5-naphthalene diisocyanate (NDI) in the future, and the synthesis of 1,5-naphthalene dicarbamate is the key to this route.

In the US4278805 document, a method for catalytically synthesizing ethyl 1,5-naphthalene dicarbamate with 1,5-diaminonaphthalene (NDA), ethyl carbamate and ethanol as raw materials is disclosed. After reacting at 180°C for 12 hours, the conversion rate of 1,5-diaminonaphthalene (NDA) was 71%, and the selectivity was 82.8%. The method takes a long time to react and the conversion rate is not high.

Disclosed in US4593117 literature is a kind of catalyzed synthesis of 1,5-naphthalene diaminodeca with 1,5-diaminonaphthalene (NDA) and N-phenyl-O-dodecyl carbamate and dodecanol dialkyl esters. The reaction was carried out at 220° C. and 500 mbar for 5 hours, and the yield was 87%. This method has a high reaction temperature, which will lead to polymerization and cause a decrease in selectivity, and the operation is complicated.

In the literature J.Am.Chem.Soc., 1993, (115): 3778-3779, 1,5-dinitronaphthalene, CO and methanol are used as raw materials, and Pd-clay, Ru ₃ (CO) ₁₂ , 2,2'-bipyridine was used as a catalyst, reacted at 180°C and 70atm for 12 hours, and the yield of synthetic NDC was 72%. This method not only uses precious metals as catalysts, but also has high reaction pressure and long time.

Technical content of the present invention

The invention mainly solves the problems existing in the prior art such as complex process, harsh reaction conditions, low yield, high production cost, etc., thereby providing a simple and safe process, mild reaction conditions, high yield, low production cost, and no environmental pollution. Synthetic method of methyl 1,5-naphthalene dicarbamate.

Technical solution of the present invention is as follows:

The synthetic method of 1,5-naphthalene dicarbamate methyl ester is that 1,5-diaminonaphthalene reacts with dimethyl carbonate in a solvent, and catalyzes the synthesis of 1,5-naphthalene dicarbamate methyl ester, and its process steps are as follows:

(1) 1,5-diaminonaphthalene and dimethyl carbonate, catalyst, solvent are put into reactor;

(2) When heated to a temperature of 175-200°C, react for 1-4.5 hours;

(3) After the reaction is finished, cool to room temperature, take out the reaction mixture, and separate to obtain methyl 1,5-naphthalene dicarbamate.

The ratio of the amount of 1,5-diaminonaphthalene to dimethyl carbonate used in the above synthesis method is 1:10-1:25.

The ratio of the catalyst used in the above synthesis method to the amount of 1,5-diaminonaphthalene is 0.45:1-0.9:1.

The catalyst used in the above-mentioned synthetic method is: zinc carbonate, zinc sulfate, zinc nitrate in the zinc inorganic acid; zinc formate, zinc trimethyl acetate, zinc trichloroacetate, zinc oxalate, zinc propionate, Zinc butyrate, zinc isobutyrate, zinc valerate, zinc isovalerate, zinc hexanoate, zinc heptanoate, zinc isoheptanoate, zinc caprylate, zinc isooctanoate, zinc nonanoate, zinc caprate, lauryl acid Zinc, zinc myristate, zinc hexadecanoate, zinc octadecanoate, zinc behenate, zinc benzoate, zinc phenylacetate, zinc salicylate; barium acetate, magnesium acetate in acetate , manganese acetate, cadmium acetate, lead acetate, copper acetate, nickel acetate.

The solvent used in the above synthesis method is isobutanol, isopropanol, methanol, ethanol, acetone, dioxane, tetrahydrofuran, dimethyl carbonate, acetonitrile, pyridine, N,N-dimethylformamide, sulfolane , Dimethyl sulfoxide.

The concentration of 1,5-diaminonaphthalene used in the above synthesis method is 19-57g/100ml solvent.

The separation method in the above synthesis method is: filter the slurry obtained after the reaction under reduced pressure, and dry the filter cake after being treated with dilute sulfuric acid to obtain the solid product 1,5-methyl naphthalene dicarbamate; the filtrate is also obtained after vacuum distillation The solid product is methyl 1,5-naphthalene dicarbamate; the distillate solvent is recycled for reuse.

Characterized by IR, MS, NMR ¹ H, NMR ¹³ C and meta-analysis, it is methyl 1,5-naphthalene dicarbamate.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The synthetic method of the present invention uses " green chemical " dimethyl carbonate (DMC) as raw material, can realize simple and safe, pollution-free clean production.

(2) synthetic method of the present invention only by-product methyl alcohol, and methyl alcohol is the raw material of synthetic dimethyl carbonate (DMC), in conjunction with methyl alcohol and CO, _O oxidative carbonylation synthesis dimethyl carbonate (DMC) technology, In this way, "zero discharge" of the chemical process can be achieved, and an atomic economy can be realized.

(3) The reaction condition of the synthetic method of the present invention is mild, easy to operate, the catalyst used is cheap, and the product yield is high, which can reach 95%.

The specific embodiment of the present invention is as follows

Example 1

(1) 5g1,5-diaminonaphthalene (NDA), 67ml dimethyl carbonate (DMC) (NDA: DMC = 1: 25, the ratio of the amount of substance), 3.2g trimethyl zinc acetate (trimethyl Zinc acetate: NDA=0.5: 1, the ratio of the amount of substance), drops in the reactor;

(2) heating to a temperature of 180° C., and reacting for 4.5 hours;

(3) After the reaction finishes, cool to room temperature, take out the reaction mixture and separate;

(4) The method for separation is to filter the slurry obtained after the reaction is finished under reduced pressure. The filtrate was distilled under reduced pressure to obtain solid product 1,5-naphthalene dicarbamate methyl ester (NDC); while the filter cake was treated with dilute sulfuric acid, solid product 1,5-naphthalene dicarbamate methyl ester (NDC) was also obtained. The distillate is recycled for reuse.

Product is through IR, MS, NMR ¹ H, NMR ¹³ C and meta-analysis, is 1,5-naphthalene dicarbamate methyl ester (NDC), and the results are as follows:

IR (cm ^-1 ): 3291, 2962, 1702, 1601, 1502, 1335, 1261, 1099, 791;

MS: 274, 242, 210, 183, 169, 156, 128, 115, 102, 59;

NMR ¹ H (ppm): 9.54786, 7.58014, 7.52888, 7.90431, 7.86363, 7.48920, 3.69039;

NMR ¹³ C (ppm): 155.460, 133.987, 128.691, 125.465, 121.553, 119.505, 51.893;

Meta-analysis: Measured values: C: 61.46%, H: 4.85%, N: 10.05%;

True value: C: 61.31%, H: 5.11%, N: 10.22%;

The product is measured by high-performance liquid chromatography (HPLC), and the conversion rate of 1,5-diaminonaphthalene (NDA) is 100%, the yield of 1,5-naphthalene dicarbamate (NDC) is 95.0%, and the catalyst specific activity is 154.9gNDC/ (mol-cat).h.

Example 2

(1) 5g1,5-diaminonaphthalene (NDA), 67ml dimethyl carbonate (DMC) (NDA: DMC=1: 25, the ratio of the amount of substance), 60ml of cyclobutane, 3.0g zinc propionate (zinc propionate: NDA=0.45: 1, the ratio of the amount of substance), drop in the reactor;

(2) heating to a temperature of 185° C., and reacting for 4 hours;

(3) After the reaction was finished, it was cooled to room temperature, and the reaction mixture was taken out for separation to obtain white solid methyl 1,5-naphthalene dicarbamate (NDC). Separation method is with embodiment 1.

As determined by HPLC, the conversion rate of 1,5-diaminonaphthalene (NDA) is 100%, the yield of methyl 1,5-naphthalene dicarbamate (NDC) is 92.2%, and the catalyst specific activity is 87.1gNDC/(mol-cat).h .

Example 3

(1) 5g1,5-diaminonaphthalene (NDA), 27ml dimethyl carbonate (DMC) (NDA: DMC = 1: 10, the ratio of the amount of substance), 67ml of dimethyl sulfoxide, 4.7g ammonium Zinc acid (zinc valerate: NDA=0.75: 1, the ratio of the amount of substance) is dropped into the reactor;

(2) heating to a temperature of 190° C., and reacting for 3 hours;

(3) After the reaction is finished, cool to room temperature, take out the reaction mixture and separate; just obtain white solid 1,5-methyl naphthalene dicarbamate (NDC). Separation method is with embodiment 1.

As determined by HPLC, the yield of methyl 1,5-naphthalene dicarbamate (NDC) was 78.7%.

Example 4

(1) With 5g1,5-diaminonaphthalene (NDA), 54ml dimethyl carbonate (DMC) (NDA:DMC=1:20, the ratio of the amount of substance), 50ml of cyclobutane, 3.2g trimethyl Zinc acetate (zinc trimethylacetate: NDA=0.5: 1, the ratio of the amount of substance) is dropped into the reactor;

(2) heating to a temperature of 175° C., and reacting for 2.5 hours;

(3) After the reaction is finished, cool to room temperature, take out the reaction mixture and separate; just obtain white solid 1,5-methyl naphthalene dicarbamate (NDC). Separation method is with embodiment 1.

As determined by HPLC, the yield of methyl 1,5-naphthalene dicarbamate (NDC) was 81.4%.

Example 5

(1) 5g1,5-diaminonaphthalene (NDA), 67ml dimethyl carbonate (DMC) (NDA: DMC=1: 25, the ratio of the amount of substance), 55ml of acetonitrile, 4.4g zinc dodecanoate (zinc dodecanoate: NDA=0.8: 1, the ratio of the amount of substance), drop in the reactor;

(2) heating to a temperature of 190° C., and reacting for 4.5 hours;

(3) After the reaction is finished, cool to room temperature, take out the reaction mixture and separate; just obtain white solid 1,5-methyl naphthalene dicarbamate (NDC). Separation method is with embodiment 1.

As determined by HPLC, the yield of methyl 1,5-naphthalene dicarbamate (NDC) was 89.7%.

Example 6

(1) 5g1,5-diaminonaphthalene (NDA), 27ml dimethyl carbonate (DMC) (NDA:DMC=1:10, the ratio of the amount of substance), 50ml of N,N-dimethylformamide , 3.9g zinc valerate (zinc valerate: NDA=0.45: 1, the ratio of the amount of substance), drops in the reactor;

(2) heating to a temperature of 200° C., and reacting for 1 hour;

(3) After the reaction is finished, cool to room temperature, take out the reaction mixture and separate; just obtain white solid 1,5-methyl naphthalene dicarbamate (NDC). Separation method is with embodiment 1.

As determined by HPLC, the yield of methyl 1,5-naphthalene dicarbamate (NDC) was 21.5%.

Example 7

(1) 5g1,5-diaminonaphthalene (NDA), 67ml dimethyl carbonate (DMC) (NDA: DMC = 1: 25, the ratio of the amount of substance), 6.0g zinc octadecanoate (octadecyl Zinc acid: NDA=0.45: 1, the ratio of the amount of substance), drops in the reactor;

(2) heating to a temperature of 175° C., and reacting for 4.5 hours;

(3) After the reaction is finished, cool to room temperature, take out the reaction mixture and separate; just obtain white solid 1,5-methyl naphthalene dicarbamate (NDC). Separation method is with embodiment 1.

As determined by HPLC, the yield of methyl 1,5-naphthalene dicarbamate (NDC) was 93.2%.

Claims (7)

1. a kind of synthetic method of 1,5-methylnaphthalene dicarbamate, is characterized in that: its processing step is as follows: (1) 1,5-diaminonaphthalene and dimethyl carbonate, catalyst, solvent are put into reactor; (2) When heated to a temperature of 175°C to 200°C, react for 1 to 4.5 hours; (3) After the reaction is finished, cool to room temperature, take out the reaction mixture, and separate to obtain methyl 1,5-naphthalene dicarbamate. 2. according to the synthetic method of said 1,5-naphthalene dicarbamate methyl esters of claim 1, it is characterized in that: the ratio of the amount of substance of 1,5-diaminonaphthalene and dimethyl carbonate used is 1: 10～1:25. 3. according to claim 1 said 1, the synthetic method of 5-naphthalene dicarbamic acid methyl ester is characterized in that: the catalyst of use and 1, the ratio of the amount of substance of 5-diaminonaphthalene is 0.45: 1～0.9 : 1. 4. according to the synthetic method of said 1,5-naphthalene dicarbamate of claim 1, it is characterized in that: the catalyst used is: zinc carbonate, zinc sulfate, zinc nitrate in inorganic acid zinc; organic acid zinc Zinc formate, zinc trimethylacetate, zinc trichloroacetate, zinc oxalate, zinc propionate, zinc butyrate, zinc isobutyrate, zinc valerate, zinc isovalerate, zinc hexanoate, zinc heptanoate, isobutyrate Zinc heptanoate, zinc caprylate, zinc isooctanoate, zinc nonanoate, zinc caprate, zinc dodecanoate, zinc myristate, zinc hexadecanoate, zinc octadecanoate, zinc behenate, Zinc benzoate, zinc phenylacetate, zinc salicylate; barium acetate, magnesium acetate, manganese acetate, cadmium acetate, lead acetate, copper acetate, nickel acetate in acetate. 5. according to the said 1 of claim 1, the synthetic method of 5-naphthalene dicarbamic acid methyl ester is characterized in that: used solvent is isobutanol, Virahol, methyl alcohol, ethanol, acetone, dioxane , tetrahydrofuran, dimethyl carbonate, acetonitrile, pyridine, N,N-dimethylformamide, sulfolane, dimethyl sulfoxide. 6. according to the synthetic method of said 1,5-naphthalene diaminocarbamate of claim 1, it is characterized in that: the concentration of used 1,5-diaminonaphthalene is 19～57g/100ml solvent. 7. according to the synthetic method of said 1,5-naphthalene dicarbamate of claim 1, it is characterized in that: the separation method of product is: the slurry decompression filtration that obtains after reaction finishes, and filter cake is processed with dilute sulfuric acid After drying, the solid product methyl 1,5-naphthalene dicarbamate is obtained; the filtrate is distilled under reduced pressure to obtain the solid product 1,5-methyl naphthalene dicarbamate; the solvent of the distillate is recovered and reused.