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WO2016092499A1 - An improved process for the production of quaternary pyridinium salts - Google Patents

An improved process for the production of quaternary pyridinium salts Download PDF

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Publication number
WO2016092499A1
WO2016092499A1 PCT/IB2015/059507 IB2015059507W WO2016092499A1 WO 2016092499 A1 WO2016092499 A1 WO 2016092499A1 IB 2015059507 W IB2015059507 W IB 2015059507W WO 2016092499 A1 WO2016092499 A1 WO 2016092499A1
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formula
acid
group
catalyst
quaternary pyridinium
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PCT/IB2015/059507
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French (fr)
Inventor
Anuj PANDEY
Sheo Prakash PANDEY
Pradeep Kumar Verma
Ashutosh Agarwal
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Jubilant Life Sciences Limited
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
    • C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members

Definitions

  • This invention in general, relates to an improved process for the production of quaternary ammonium compounds. More particularly, the present invention provides an improved one pot, cost effective and eco-friendly process for large scale industrial production of quaternary pyridinium salts of formula (I) and their hydrates with high yield and purity.
  • Quaternary ammonium salts have been remarkably important as starting materials for medicines and quasi-drugs and cosmetics, phase-transfer catalysts, ionized solvents etc.
  • quaternary pyridinium salts have been found to be useful mainly as an antibacterial agent thereby indicating an increase in their demand.
  • Pyridinium salts (C 12 and C 16 ) are used as solubilizers for water insoluble compounds in analytical chemistry.
  • a compound with a C 16 side chain on the pyridinium ring (cetylpyridinium, CP) is being used for the protection of the poultry and medical devices against bacterial contamination. They are also used as antibacterial agent in mouth wash and toothpastes.
  • CP is being used in chewing gums as anti-plaque agents, in the dentistry as periodontal agent and in ophthalmic products as preservative.
  • the surface activity of CP predicted its ability to form the micelles which is being used for the removal of the pollutants (e.g. arsenic, perchlorate) from the ground water and also for the removal of the heavy metals from solutions.
  • Pyridinium detergents are being used as carriers for improving adsorption of the oligonucleotides at the phospholipid membrane.
  • Pyridinium salts are also used as cationic surfactant in ink, toner and nano materials, corrosion inhibitors and hard surface cleaning agents.
  • the pyridinium analogues with the alkyl chains longer than Cio are known as nicotinic receptor antagonists.
  • Pyridinium salts bearing shorter alkyl chains are useful as cholinesterase inhibitors.
  • Polish Patent No. PL 149740 discloses a method for the purification of cetylpyridinium chloride (CPC).
  • CPC cetylpyridinium chloride
  • the process involves condensation of cetyl chloride with dehydrated and purified pyridine at 110 °C for 80 hours.
  • the purification of CPC obtained involves dissolving the crude CPC into ethanol, charcoalizing for about 4-6 hours, cooling and left to settle for 12 hours.
  • the solution obtained is filtered and greenish yellow CPC obtained is extracted with acetone, filtered and dried to get pure product. Long reaction times along with tedious purification steps make this method commercially unviable.
  • EP Patent No. 1125927 discloses a method for the preparation of cetylpyridinium chloride monohydrate. The process involves reacting cetyl chloride (0.44 mole) with 1.8 mole of pyridine under nitrogen atmosphere in an autoclave at 2kg/cm of pressure followed by agitation at 180 °C. The product is crystallized with methyl ethyl ketone to obtain powdery crystal of CPC which was treated with water to obtain CPC monohydrate.
  • US Patent No. 5041664 discloses a continuous process for preparing dimethylcocoalkylbenzylammonium chloride which comprises reacting benzyl amine with dimethylcocoalkylamine, over alumina in the presence of isopropanol at a temperature of 120 °C and at a pressure of 1000 psi. High temperature and pressure reaction conditions make the process commercially unviable.
  • Marek et al in Molecules, 2010, 15, 1967 reported the preparation of pyridinium salts differing in the alkyl chains (C 8 to C 2 o) by refluxing a mixture of pyridine and alkyl halide in dry ethanol for 40 hours. The solution is evaporated under reduced pressure and the crude oily product crystallized from ether. Satisfactory purity is obtained after several crystallizations from ether suspensions. The compounds with C 18 to C 2 o alkyl chains are contaminated with starting material and hence crystallized from acetone.
  • Chinese Patent Application No. CN 103539727A discloses preparation of CPC via condensation of cetyl chloride and pyridine at 100-125 °C for 10-14 hours. After completion of the reaction, pyridine is recycled via depressurization, and an alcohol solvent and active carbon are added for decolourization to obtain crude CPC which is subjected to two purifications. The first purification is done with a mixture of acetone and water followed with the second purification with a mixture of alcohol and water. Thus, this process is cumbersome as involve several steps. Thus, the processes disclosed in the prior art involve multiple steps for purification which results in increase in number of operations and reduced yield, consequently making the process costly and uneconomical.
  • Formula (II) Formula (III) ii) optionally, converting the quaternary pyridinium salt of formula (I) to its hydrate, wherein,
  • R represents a hydrogen atom, an optionally substituted C 1 -C5 alkyl group or an optionally substituted C 1 -C5 alkoxyl group.
  • R can be a hydrogen atom, a straight chain or branched C 1 -C5 alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, isopentyl, sec-pentyl, tert-pentyl, and the likes; a hydroxy C 1 -C5 alkyl, such as hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxyisopropyl, 1-hydroxybutyl, 2-hydroxybutyl, 3-hydroxybutyl and the likes; an optionally-substituted C 1 -C5 alkoxyl, such as methoxy, ethoxy, propoxy, trifluoromethoxy and the likes; R' is selected from Ci 2 -C 2 o
  • n is any integer from 11-19;
  • X is halogen selected from chloro, bromo, fluoro and iodo.
  • a large scale industrial process for producing quaternary pyridinium salts of formula (I) and hydrates thereof comprises reacting pyridine compound of formula (II) with alkyl halide of formula (III) in the presence of catalyst, wherein the catalyst is selected from the group consisting of acid, amine and their salts, chelating agent, and mixtures thereof.
  • the present invention in general, relates to a large scale industrial process for producing quaternary pyridinium salts and hydrates thereof. More particularly, the present invention provides a cost effective, eco-friendly and less capital intensive large scale industrial process for producing quaternary pyridinium salts and hydrates thereof with high yield and purity.
  • the present invention involves a large scale industrial process for producing quaternary pyridinium salts and hydrates thereof, which is easy to operate, involving less operational steps and minimum effluent load generation thereby making the process commercially viable.
  • the process for the production of quaternary pyridinium salts of formula (I) and hydrates thereof comprises of reacting pyridine compound of formula (II) with alkyl halide of formula (III) in the presence of a catalyst to form quaternary pyridinium salt of formula (I) and optionally, converting the quaternary pyridinium salt of formula (I) to its hydrate.
  • the process for the production of hydrates of quaternary pyridinium salts of formula (I) is one pot process.
  • the catalyst is selected from the group consisting of acid, amine and their salts, chelating agent and/or mixtures thereof.
  • the amount of acid, amine, chelating agent can vary in the range of 0-100% by weight of the catalyst.
  • the acid used as catalyst in the present invention is selected from the group consisting of organic acid, inorganic acid and mixtures thereof.
  • the acid used as catalyst herein is selected from the group consisting of acetic acid, formic acid, oxalic acid, benzoic acid, hydrochloric acid, sulfuric acid, phosphoric acid and mixtures thereof.
  • the amine used as catalyst in the present invention is selected from the group consisting of organic amine, inorganic amine, their salts and mixtures thereof.
  • the amine used as catalyst herein is selected from the group consisting of N-methyl morphline, isopropyl ethyl amine, propyl ethyl amine, triethylamine, trimethylamine, ethanolamine, chloramines, piperidine, pyridine, their salts and mixtures thereof.
  • the chelating agent used as catalyst herein is selected from the group consisting of ethylenediaminetetraacetic acid (EDTA); N,N- bis(carboxymethyl)glycine (NDTA); diethylenetriaminepentaacetic acid (DTPA); nitrilotriacetic (NTA) acid; 2,3-dimercapto-l-propanol (dimercaprol); porphine and mixtures thereof.
  • reaction of pyridine compound of formula (II) with alkyl halide of formula (III) is carried out in the temperature range of 0 to 175°C, preferably between 75-150 °C.
  • the process is carried out in the absence of solvent.
  • the step of converting the quaternary pyridinium salt of formula (I) to its hydrate is carried out optionally in the presence of solvent.
  • the solvent used is selected from the group consisting of aliphatic alcohol such as methanol, ethanol, n-proponal, isopropanol, n-butanol, iso-butanol; ketone such as acetone, methyl isobutyl ketone, cyclohexanone, methyl ethyl ketone; ester such as ethyl aceate, propyl acetate, butyl acetate, methyl isobutyrate and mixtures thereof.
  • the solvent used in the isolation is recovered and reused.
  • Isolation of compound of formula (I) and hydrates thereof can be carried out by the techniques known in the art such as filtration, centrifugation, nutch filtration etc.
  • compounds of formula (I) and hydrates prepared by the process of the present invention, as anti-bacterial agent in poultry, anti-plaque agents in chewing gums and dentistry, surfactant in detergents, nicotine receptor antagonists, cholinesterase inhibitors, remover of pollutants, heavy metals, solubilizers for water insoluble compounds in analytical chemistry and starting materials for medicines and quasi drugs and cosmetics.
  • Cetyl chloride (100 g), pyridine (250 g) and catalyst (2 g containing the mixture of EDTA, N-methyl morpholine, N,N-bis(carboxymethyl) glycine and phosphoric acid) were charged into a round bottom flask, heated to 90-100 °C and maintained for 6-8 hours. After the completion of reaction, the mass was cooled, filtered and washed with ethyl acetate to get crystalline cetylpyridinium chloride (126.5 g) with 99.5% purity. The product was confirmed by m.p., mass spectroscopy, 1H NMR and 13 C NMR.
  • Cetyl chloride (100 g), pyridine (300 g) and catalyst (2 g containing the mixture of isopropyl ethyl amine, N-methyl morpholine, oxalic acid and sulfuric acid) were charged into a round bottom flask, heated to 90-100 °C and maintained for 6-8 hours. After the completion of reaction, the mass was cooled, filtered and the cake was charged to a mixture of methyl isobutyl ketone (200 g) and water (7 g). Mass was agitated to get crystalline cetylpyridinium chloride monohydrate (120 g) with 99.6% purity. The solvent and unreacted pyridine was recovered and reused in next batch. The product was confirmed by m.p., mass spectroscopy, 1H NMR and 13 C NMR.
  • Cetyl chloride (10 kg), recovered pyridine (28 kg) and catalyst (0.2 kg containing the mixture of formic acid, propyl ethyl amine, N,N-bis(carboxymethyl) glycine and hydrochloric acid) were charged into a round bottom flask, heated to 90-100 °C and maintained for 6-8 hours. After the completion of reaction, the mass was cooled, filtered and the product obtained was washed with recovered methyl isobutyl ketone to get crystalline cetylpyridinium chloride (12.6 kg) with 99.5% purity. The product was confirmed by m.p., mass spectroscopy, 1H NMR and 13 C NMR.
  • Cetyl chloride (100 g), 2-methylpyridine (250 g) and catalyst (2.0 g containing the mixture of triethylamine, EDTA, benzoic acid, sulfuric acid and formic acid) were charged into a round bottom flask, heated to 120-135 °C and maintained for 25-30 hours. After the completion of reaction, the mass was cooled, filtered and the product obtained was washed with ethyl acetate to get crystalline l-hexadecyl-2-methyl pyridinium chloride (120 g) with 99.2% purity. The product was confirmed by mass spectroscopy, 1 H NMR and 13 C NMR.
  • Cetyl chloride (100 g), 3-methyl pyridine (250 g) and catalyst (2.0 g containing the mixture of formic acid, propyl ethyl amine, N,N-bis(carboxymethyl)glycine and hydrochloric acid) were charged into a round bottom flask, heated to 130-140 °C and maintained for 15-16 hours. After the completion of reaction, the mass was cooled, filtered and the product obtained was washed with ethyl acetate to get crystalline l-hexadecyl-3 -methyl pyridinium chloride (122 g) with 99.8% purity. The product was confirmed by mass spectroscopy, 1H NMR and 13 C NMR.

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Abstract

Disclosed herein is cost effective and eco-friendly process for producing quaternary pyridinium salts and their hydrates thereof, with high yield and purity at industrial scale.

Description

AN IMPROVED PROCESS FOR THE PRODUCTION OF QUATERNARY
PYRIDINIUM SALTS
Field of the Invention
This invention, in general, relates to an improved process for the production of quaternary ammonium compounds. More particularly, the present invention provides an improved one pot, cost effective and eco-friendly process for large scale industrial production of quaternary pyridinium salts of formula (I) and their hydrates with high yield and purity.
Background of the Invention
Quaternary ammonium salts have been remarkably important as starting materials for medicines and quasi-drugs and cosmetics, phase-transfer catalysts, ionized solvents etc. Among the salts, quaternary pyridinium salts have been found to be useful mainly as an antibacterial agent thereby indicating an increase in their demand.
Pyridinium salts (C12 and C16) are used as solubilizers for water insoluble compounds in analytical chemistry. A compound with a C16 side chain on the pyridinium ring (cetylpyridinium, CP) is being used for the protection of the poultry and medical devices against bacterial contamination. They are also used as antibacterial agent in mouth wash and toothpastes. CP is being used in chewing gums as anti-plaque agents, in the dentistry as periodontal agent and in ophthalmic products as preservative. The surface activity of CP predicted its ability to form the micelles which is being used for the removal of the pollutants (e.g. arsenic, perchlorate) from the ground water and also for the removal of the heavy metals from solutions. It is also being used as surface stabilizer in pharmaceutical products. Pyridinium detergents are being used as carriers for improving adsorption of the oligonucleotides at the phospholipid membrane. Pyridinium salts are also used as cationic surfactant in ink, toner and nano materials, corrosion inhibitors and hard surface cleaning agents. The pyridinium analogues with the alkyl chains longer than Cio are known as nicotinic receptor antagonists. Pyridinium salts bearing shorter alkyl chains are useful as cholinesterase inhibitors.
In the prior art various methods are reported for the preparation of quaternary pyridinium salts. Knight et al in J. Chem. Soc, 1938, 682 reported a method for preparing dodecyl pyridinium chloride by reacting dodecyl chloride with pyridine at 100 °C for 24 hours, but the yield is very low 1.7%.
Shelton et al in J. Am. Chem. Soc, 1946, 68, 757 reported a method involving the reaction of an alkyl halide with 10 to 30% excess amount of pyridine at temperatures from 60 to 130 °C for 8 to 16 hours to afford 95% quaternary pyridinium salt. In this method rate of reaction is increased by using the excess of amine. Also for getting pure product one or two crystallization are done after the completion of reaction.
Barni et al in J. Het. Chem., 1986, 23, 209 reported the reaction of 4-methyl pyridine with cetyl iodide under refluxing for 6 hours to obtain 4-methyl cetylpyridinium iodide with 75% yield.
Polish Patent No. PL 149740 discloses a method for the purification of cetylpyridinium chloride (CPC). The process involves condensation of cetyl chloride with dehydrated and purified pyridine at 110 °C for 80 hours. The purification of CPC obtained involves dissolving the crude CPC into ethanol, charcoalizing for about 4-6 hours, cooling and left to settle for 12 hours. The solution obtained is filtered and greenish yellow CPC obtained is extracted with acetone, filtered and dried to get pure product. Long reaction times along with tedious purification steps make this method commercially unviable.
EP Patent No. 1125927 discloses a method for the preparation of cetylpyridinium chloride monohydrate. The process involves reacting cetyl chloride (0.44 mole) with 1.8 mole of pyridine under nitrogen atmosphere in an autoclave at 2kg/cm of pressure followed by agitation at 180 °C. The product is crystallized with methyl ethyl ketone to obtain powdery crystal of CPC which was treated with water to obtain CPC monohydrate.
US Patent No. 5041664 discloses a continuous process for preparing dimethylcocoalkylbenzylammonium chloride which comprises reacting benzyl amine with dimethylcocoalkylamine, over alumina in the presence of isopropanol at a temperature of 120 °C and at a pressure of 1000 psi. High temperature and pressure reaction conditions make the process commercially unviable.
Marek et al in Molecules, 2010, 15, 1967 reported the preparation of pyridinium salts differing in the alkyl chains (C8 to C2o) by refluxing a mixture of pyridine and alkyl halide in dry ethanol for 40 hours. The solution is evaporated under reduced pressure and the crude oily product crystallized from ether. Satisfactory purity is obtained after several crystallizations from ether suspensions. The compounds with C18 to C2o alkyl chains are contaminated with starting material and hence crystallized from acetone.
Chinese Patent Application No. CN 103539727A discloses preparation of CPC via condensation of cetyl chloride and pyridine at 100-125 °C for 10-14 hours. After completion of the reaction, pyridine is recycled via depressurization, and an alcohol solvent and active carbon are added for decolourization to obtain crude CPC which is subjected to two purifications. The first purification is done with a mixture of acetone and water followed with the second purification with a mixture of alcohol and water. Thus, this process is cumbersome as involve several steps. Thus, the processes disclosed in the prior art involve multiple steps for purification which results in increase in number of operations and reduced yield, consequently making the process costly and uneconomical. Further, the processes disclosed in the prior art can be used for producing small batches of the desired products in low yield, hence making the processes unsuitable for large-scale production. In view of the increasing demand for producing quaternary pyridinium salts and hydrates thereof, of high yield and purity, it is therefore desirable to develop a commercially and economically viable process for industrial manufacturing of quaternary pyridinium salts and hydrates thereof with high yield and purity which can address the above mentioned problems associated with the known processes. Summary of the Invention
It is a principal object of the present invention to provide a process for producing quaternary pyridinium salts and hydrates thereof at industrial scale, wherein the process enables single pot production of the compounds.
It is another object of the invention to provide a cost effective and commercially viable process for producing quaternary pyridinium salts and hydrates thereof at industrial scale, wherein the process provides product with desired purity, involving simple isolation steps, avoiding multi stage operations for purification.
It is another object of the present invention to provide an eco-friendly and carbon efficient process for producing quaternary pyridinium salts and hydrates thereof at industrial scale, wherein the process enables production of highly pure quaternary pyridinium salts at industrial scale with minimum generation of effluents.
In accordance with object of the present invention, there is provided a large scale industrial process for the production of quaternary pyridinium salts of formula (I) and hydrates thereof, wherein the process comprises:
Figure imgf000005_0001
Formula (I) reacting pyridine compound of formula (II) with alkyl halide of formula (III) presence of a catalyst to obtain quaternary pyridinium salt of formula (I),
Figure imgf000005_0002
Formula (II) Formula (III) ii) optionally, converting the quaternary pyridinium salt of formula (I) to its hydrate, wherein,
R represents a hydrogen atom, an optionally substituted C1-C5 alkyl group or an optionally substituted C1-C5 alkoxyl group.
More specifically, R can be a hydrogen atom, a straight chain or branched C1-C5 alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, isopentyl, sec-pentyl, tert-pentyl, and the likes; a hydroxy C1-C5 alkyl, such as hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxyisopropyl, 1-hydroxybutyl, 2-hydroxybutyl, 3-hydroxybutyl and the likes; an optionally-substituted C1-C5 alkoxyl, such as methoxy, ethoxy, propoxy, trifluoromethoxy and the likes; R' is selected from Ci2-C2o alkyl group;
n is any integer from 11-19;
X is halogen selected from chloro, bromo, fluoro and iodo.
In accordance with another object of the present invention, there is provided a large scale industrial process for producing quaternary pyridinium salts of formula (I) and hydrates thereof, wherein the process comprises reacting pyridine compound of formula (II) with alkyl halide of formula (III) in the presence of catalyst, wherein the catalyst is selected from the group consisting of acid, amine and their salts, chelating agent, and mixtures thereof.
In accordance with yet another object of the present invention there is provided a large scale industrial process for producing quaternary pyridinium salts of formula (I) and hydrates thereof, wherein the reaction is performed in the temperature range of 0 - 175 °C.
Detailed Description of the Invention
While this specification concludes with claims particularly pointing out and distinctly claiming that, which is regarded as the invention, it is anticipated that the invention can be more readily understood through reading the following detailed description of the invention and study of the included examples.
The present invention, in general, relates to a large scale industrial process for producing quaternary pyridinium salts and hydrates thereof. More particularly, the present invention provides a cost effective, eco-friendly and less capital intensive large scale industrial process for producing quaternary pyridinium salts and hydrates thereof with high yield and purity.
The present invention involves a large scale industrial process for producing quaternary pyridinium salts and hydrates thereof, which is easy to operate, involving less operational steps and minimum effluent load generation thereby making the process commercially viable.
It has been observed during the preparation of quaternary pyridinium salts and hydrates of the present invention that for reducing reaction time, if the temperature of the reaction is increased then the color of the product deviates from white. Alternatively, if the temperature is reduced then the rate of reaction becomes slow thereby resulting in incomplete reaction. However, by using the catalyst of the present invention, the temperature required for condensation of pyridine compounds with alky halide is reduced and conversion is also complete resulting in the formation of product with desired purity. According to the present invention, the process for the production of quaternary pyridinium salts of formula (I) and hydrates thereof, comprises of reacting pyridine compound of formula (II) with alkyl halide of formula (III) in the presence of a catalyst to form quaternary pyridinium salt of formula (I) and optionally, converting the quaternary pyridinium salt of formula (I) to its hydrate.
Figure imgf000007_0001
Formula (I) Formula (II) Formula (III) wherein R, R', n and X are the same as defined earlier.
According to the present invention, the process for the production of hydrates of quaternary pyridinium salts of formula (I) is one pot process.
According to the present invention, the catalyst is selected from the group consisting of acid, amine and their salts, chelating agent and/or mixtures thereof. The amount of acid, amine, chelating agent can vary in the range of 0-100% by weight of the catalyst.
The acid used as catalyst in the present invention, is selected from the group consisting of organic acid, inorganic acid and mixtures thereof. The acid used as catalyst herein is selected from the group consisting of acetic acid, formic acid, oxalic acid, benzoic acid, hydrochloric acid, sulfuric acid, phosphoric acid and mixtures thereof.
The amine used as catalyst in the present invention, is selected from the group consisting of organic amine, inorganic amine, their salts and mixtures thereof. The amine used as catalyst herein is selected from the group consisting of N-methyl morphline, isopropyl ethyl amine, propyl ethyl amine, triethylamine, trimethylamine, ethanolamine, chloramines, piperidine, pyridine, their salts and mixtures thereof.
According to the present invention, the chelating agent used as catalyst herein is selected from the group consisting of ethylenediaminetetraacetic acid (EDTA); N,N- bis(carboxymethyl)glycine (NDTA); diethylenetriaminepentaacetic acid (DTPA); nitrilotriacetic (NTA) acid; 2,3-dimercapto-l-propanol (dimercaprol); porphine and mixtures thereof.
According to the present invention, the reaction of pyridine compound of formula (II) with alkyl halide of formula (III) is carried out in the temperature range of 0 to 175°C, preferably between 75-150 °C. The process is carried out in the absence of solvent.
According to the present invention, the step of converting the quaternary pyridinium salt of formula (I) to its hydrate is carried out optionally in the presence of solvent. The solvent used is selected from the group consisting of aliphatic alcohol such as methanol, ethanol, n-proponal, isopropanol, n-butanol, iso-butanol; ketone such as acetone, methyl isobutyl ketone, cyclohexanone, methyl ethyl ketone; ester such as ethyl aceate, propyl acetate, butyl acetate, methyl isobutyrate and mixtures thereof.
According to the present invention, the solvent used in the isolation is recovered and reused. Isolation of compound of formula (I) and hydrates thereof, can be carried out by the techniques known in the art such as filtration, centrifugation, nutch filtration etc. According to the present invention, there is provided use of compounds of formula (I) and hydrates, prepared by the process of the present invention, as antibacterial agent, phase transfer catalyst, ionized solvents, solubilizers, in cosmetics and pharmaceuticals.
According to another embodiment of the present invention, there is provided use of compounds of formula (I) and hydrates, prepared by the process of the present invention, as anti-bacterial agent in poultry, anti-plaque agents in chewing gums and dentistry, surfactant in detergents, nicotine receptor antagonists, cholinesterase inhibitors, remover of pollutants, heavy metals, solubilizers for water insoluble compounds in analytical chemistry and starting materials for medicines and quasi drugs and cosmetics.
According to yet another embodiment aspect of the present invention, there is provided use of compounds of formula (I) and hydrates, prepared by the process of the present invention, as antibacterial agent in mouthwash and toothpaste, periodontal agent in dentistry, cationic surfactant in ink, toner and nano materials, preservative in ophthalmic products, surface stabilizer in pharmaceutical products, disinfectant in medical devices, corrosion inhibitor, and hard surface cleaning agent. The present invention is further illustrated below with reference to the following examples without intending to limit the scope of the invention in any manner. Example -1
Synthesis of cetylpyridinium chloride
Cetyl chloride (100 g), pyridine (250 g) and catalyst (2 g containing the mixture of EDTA, N-methyl morpholine, N,N-bis(carboxymethyl) glycine and phosphoric acid) were charged into a round bottom flask, heated to 90-100 °C and maintained for 6-8 hours. After the completion of reaction, the mass was cooled, filtered and washed with ethyl acetate to get crystalline cetylpyridinium chloride (126.5 g) with 99.5% purity. The product was confirmed by m.p., mass spectroscopy, 1H NMR and 13C NMR.
Example -2 Synthesis of cetylpyridinium chloride monohydrate
Cetyl chloride (100 g), pyridine (300 g) and catalyst (2 g containing the mixture of isopropyl ethyl amine, N-methyl morpholine, oxalic acid and sulfuric acid) were charged into a round bottom flask, heated to 90-100 °C and maintained for 6-8 hours. After the completion of reaction, the mass was cooled, filtered and the cake was charged to a mixture of methyl isobutyl ketone (200 g) and water (7 g). Mass was agitated to get crystalline cetylpyridinium chloride monohydrate (120 g) with 99.6% purity. The solvent and unreacted pyridine was recovered and reused in next batch. The product was confirmed by m.p., mass spectroscopy, 1H NMR and 13C NMR.
Example -3 Synthesis of cetylpyridinium chloride
Cetyl chloride (10 kg), recovered pyridine (28 kg) and catalyst (0.2 kg containing the mixture of formic acid, propyl ethyl amine, N,N-bis(carboxymethyl) glycine and hydrochloric acid) were charged into a round bottom flask, heated to 90-100 °C and maintained for 6-8 hours. After the completion of reaction, the mass was cooled, filtered and the product obtained was washed with recovered methyl isobutyl ketone to get crystalline cetylpyridinium chloride (12.6 kg) with 99.5% purity. The product was confirmed by m.p., mass spectroscopy, 1H NMR and 13C NMR. Example -4
Synthesis of l-hexadecyl-2-methyl pyridinium chloride
Cetyl chloride (100 g), 2-methylpyridine (250 g) and catalyst (2.0 g containing the mixture of triethylamine, EDTA, benzoic acid, sulfuric acid and formic acid) were charged into a round bottom flask, heated to 120-135 °C and maintained for 25-30 hours. After the completion of reaction, the mass was cooled, filtered and the product obtained was washed with ethyl acetate to get crystalline l-hexadecyl-2-methyl pyridinium chloride (120 g) with 99.2% purity. The product was confirmed by mass spectroscopy, 1 H NMR and 13 C NMR.
Example -5 Synthesis of l-hexadecyl-3-methyl pyridinium chloride
Cetyl chloride (100 g), 3-methyl pyridine (250 g) and catalyst (2.0 g containing the mixture of formic acid, propyl ethyl amine, N,N-bis(carboxymethyl)glycine and hydrochloric acid) were charged into a round bottom flask, heated to 130-140 °C and maintained for 15-16 hours. After the completion of reaction, the mass was cooled, filtered and the product obtained was washed with ethyl acetate to get crystalline l-hexadecyl-3 -methyl pyridinium chloride (122 g) with 99.8% purity. The product was confirmed by mass spectroscopy, 1H NMR and 13C NMR.
Example -6
Synthesis of l-hexadecyl-4-methyl pyridinium chloride Cetyl chloride (100 g), 4-methyl pyridine (250 g) and catalyst (2.0 g containing the mixture of EDTA, N-methyl morpholine, N,N-bis(carboxymethyl)glycine and phosphoric acid) were charged into a round bottom flask, heated to 135-145 °C and maintained for 8-10 hours. After the completion of reaction, the mass was cooled, filtered and the product obtained was washed with ethyl acetate to get crystalline l-hexadecyl-4-methyl pyridinium chloride (118g) with 99.0% purity. The product was confirmed by mass spectroscopy, 1H NMR and 13C NMR.

Claims

We claim:
1. A process for the production of quaternary pyridinium salts of formula (I) and hydrates thereof, wherein the process comprises:
Figure imgf000011_0001
Formula (I) reacting pyridine compound of formula (II) with alkyl halide of formula (III) presence of a catalyst to form quaternary pyridinium salt of formula (I),
Figure imgf000011_0002
Formula (II) Formula (III) ii) optionally, converting the quaternary pyridinium salt of formula (I) to its hydrate, wherein,
R represents a hydrogen atom, an optionally substituted Q-C5 alkyl group or an optionally substituted C1-C5 alkoxyl group.
More specifically, R can be a hydrogen atom, a straight chain or branched C1-C5 alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, isopentyl, sec-pentyl, tert-pentyl, and the likes; a hydroxy C1-C5 alkyl, such as hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxyisopropyl, 1 -hydroxybutyl, 2- hydroxybutyl, 3-hydroxybutyl and the likes; an optionally-substituted C1-C5 alkoxyl, such as methoxy, ethoxy, propoxy, trifluoromethoxy and the likes;
R' is selected from C12-C20 alkyl group n is any integer from 11-19
X is halogen atom selected from chloro, bromo, fluoro and iodo group.
2. The process as claimed in claim 1, wherein the catalyst is selected from the group consisting of acid, amine and their salts, chelating agent and/or mixtures thereof.
3. The process as claimed in claim 2, wherein the catalyst is selected from the group consisting of organic acid, inorganic acid and mixtures thereof.
4. The process as claimed in claim 1 and 2, wherein the catalyst is selected from the group consisting of acetic acid, formic acid, oxalic acid, benzoic acid, hydrochloric acid, sulfuric acid, phosphoric acid and mixtures thereof.
5. The process as claimed in claim 2, wherein the catalyst is selected from the group consisting of organic amine, inorganic amine, their salts and mixtures thereof.
6. The process as claimed in claim 1 and 2, wherein the amine is selected from the group consisting of N-methyl morphline, ethylisopropyl amine, propylethyl amine, triethylamine, trimethylamine, ethanolamine, chloramines, piperidine, pyridine, their salts and mixtures thereof.
7. The process as claimed in claim 1 and 2, wherein the chelating agent is selected from the group consisting of ethylenediaminetetraacetic acid; N,N-bis(carboxymethyl)glycine, diethylenetriaminepentaacetic acid, nitrilotriacetic acid, 2,3-dimercapto-l-propanol and mixtures thereof.
8. The process as claimed in claim 1, wherein the reaction is carried out in the temperature range of 0-175 °C.
9. The process as claimed in claim 8, wherein the reaction is carried out in the temperature range of 75-150 °C.
10. The process as claimed in claim 1, wherein the step (ii) is carried out optionally in the presence of solvent selected from the group consisting of aliphatic alcohol, ketone, ester and mixtures thereof.
1. The process as claimed in claim 1, wherein the compound of formula (I) is cetylpyridinium chloride and its hydrate.
The quaternary pyridinium salts of formula (I) and hydrates, prepared by the process as claimed in any of the claims 1 to 11, as and when used as antibacterial agent, phase transfer catalyst, ionized solvents, solubilizers, in cosmetics and pharmaceuticals.
The quaternary pyridinium salts of formula (I) and hydrates, prepared by the process as claimed in any of the claims 1 to 11, as and when used as anti-bacterial agent in poultry, anti-plaque agents in chewing gums and dentistry, surfactant in detergents, nicotine receptor antagonists, choline esterase inhibitors, remover of pollutants, heavy metals, solubilizers for water insoluble compounds in analytical chemistry and starting materials for medicines and quasi drugs and cosmetics.
The quaternary pyridinium salts of formula (I) and hydrates, prepared by the process as claimed in any of the claims 1 to 11, as and when used as antibacterial agent in mouthwash and toothpaste, periodontal agent in dentistry, cationic surfactant in ink, toner and nano materials, preservative in ophthalmic products, surface stabilizer in pharmaceutical products, disinfectant in medical devices, corrosion inhibitor, and hard surface cleaning agent.
PCT/IB2015/059507 2014-12-12 2015-12-10 An improved process for the production of quaternary pyridinium salts WO2016092499A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116283751A (en) * 2023-03-17 2023-06-23 胜利油田物华化工厂 Bactericide for sewage treatment and synthetic method
US12247246B2 (en) 2017-09-26 2025-03-11 Washington University Identification of inhibitors of TcpC and TIR NADase activity

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5110929A (en) * 1986-08-07 1992-05-05 Medice Cham.-Pharm. Fabrik Putter Gmbh & Co. Kg Process for the preparation of N-alkylated quaternary nitrogen containing aromatic heterocycles
US20010018526A1 (en) * 2000-02-14 2001-08-30 Wako Pure Chemical Industries, Ltd. Method for preparation of a quaternary ammonium salt
WO2005072693A1 (en) * 2004-01-29 2005-08-11 The Procter & Gamble Company Oral care compositions comprising increased bioavailable levels of quaternary ammonium antimicrobials

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5110929A (en) * 1986-08-07 1992-05-05 Medice Cham.-Pharm. Fabrik Putter Gmbh & Co. Kg Process for the preparation of N-alkylated quaternary nitrogen containing aromatic heterocycles
US20010018526A1 (en) * 2000-02-14 2001-08-30 Wako Pure Chemical Industries, Ltd. Method for preparation of a quaternary ammonium salt
WO2005072693A1 (en) * 2004-01-29 2005-08-11 The Procter & Gamble Company Oral care compositions comprising increased bioavailable levels of quaternary ammonium antimicrobials

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US12247246B2 (en) 2017-09-26 2025-03-11 Washington University Identification of inhibitors of TcpC and TIR NADase activity
CN116283751A (en) * 2023-03-17 2023-06-23 胜利油田物华化工厂 Bactericide for sewage treatment and synthetic method

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