Potassium Carbonate → 2-Chloromethyl-3-methyl-4-(2-morpholinoethylthio)pyridine

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Reaction Steps

2-Hydroxymethyl-3-methyl-4-(2-morpholinoethylthio)pyridine (6.2 g) was dissolved in chloroform and thereto was dropwise added thionyl chloride (2 ml) under ice-cooling. The mixture was stirred at room temperature for 1 hour. After the completion of the reaction, the reaction mixture was poured into ice-water and made alkaline with potassium carbonate, followed by extraction with chloroform. The chloroform layer was dried over anhydrous magnesium sulfate and the solvent was distilled away to give 6.0 g of 2-chloromethyl-3-methyl-4-(2-morpholinoethylthio)pyridine as an oily substance. The substance was added to ethanol (60 ml) containing a solution of 5-methoxycarbonyl-2-mercaptobenzimidazole (5.1 g) and sodium hydroxide (1.6 g) in water (10 ml) and the mixture was refluxed under heating for 3.5 hours. After the completion of the reaction, the ethanol was distilled away and the residue was dissolved in water. The aqueous layer was washed with chloroform and dilute hydrochloric acid was dropwise added until crystals precipitated in the aqueous layer. The resultant crystals were collected by filtration to give 2-((3-methyl-4-(2-morpholinoethylthio)-2-pyridyl)methylthio)-1H-benzimidazole-5-carboxylic acid 7/2 hydrate, melting point 120-124° C.

Provenance & Evidence