Process for the preparation of cimetidine
AssigneeLek
InventorTeofil Zizek
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Abstract
A new and simple process for the preparation of crystalline cimetidine (N-cyano-N'-methyl-N"-{2/(5-methyl-1H-imidazole-4-yl)methylthio/ethyl}guan idine) is described, wherein cimetidine is obtained by reacting O-ethyl-S-(4-methylimidazolyl-5-methyl)dithiocarbonate hydrobromide with N-cyano-N'-methyl-N"-(2-chloroethyl)guanidine in an aqueous methylamine solution at a temperature between room temperature and the reflux temperature of the reaction mixture, whereupon the desired compound is separated. Cimetidine is a valuable drug in the therapy of the ulcer disease.
Claims4
A process for the preparation of crystalline cimetidine (N-cyano-N'-methyl-N"-{2/(5-methyl-1H-imidazole-4-yl)methylthio/ethyl}guan idine) of the formula ##STR4## characterized in that O-ethyl-S-(4-methyl-imidazolyl-5-methyl)dithiocarbonate hydrobromide is reacted with N-cyano-N'-methyl-N"-(2-chloroethyl)guanidine in an aqueous methylamine solution at a temperature between room temperature and the reflux temperature of the reaction mixture, whereupon this title compound is separated.
Dependencies are inferred from the claim text.