- Synthesis method of nizatidine drug intermediate 2-dimethylamino methyl-4-chloromethyl thiazole
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A synthesis method of a nizatidine drug intermediate 2-dimethylamino methyl-4-chloromethyl thiazole includes the following steps that 0.063 mol of 2-dimethylamino methyl-4-chloromethyl-4-aminothiazoline, 310 ml of cyclohexane, 0.92 mol of stannous chloride and 0.16-0.19 mol of an ortho-nitrotoluene solution are added into a reaction vessel provided with a stirrer and a thermometer, the stirring speed is controlled to be 150-190 rpm, the solution temperature is controlled to be 10-15 DEG C, reaction is performed for 20-25 hours, then the temperature is raised to 60-65 DEG C, the reaction continues for 4-5 hours, the solution temperature is reduced to 20-25 DEG C, solid precipitation, filtration, washing with a saline solution, washing with acetonitrile and dehydration with a dehydrating agent are performed, and recrystallization is performed in triethylamine to obtain the crystal 2-dimethylamino methyl-4-chloromethyl thiazole.
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Paragraph 0013
(2017/01/02)
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- AN IMPROVED PROCESS FOR PREPARING NIZATIDINE INTERMEDIATE
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The present invention comprises: preparation of dimethylaminothioacetamide by a novel process and its conversion to pure 4-chloromethyl-4-hydroxy-2-dimethylaminomethyl-2-thiazoline by an improved process. The 4-chloromethyl-4-hydroxy-2-dimethylaminomethyl-2-thiazoline obtained by the present invention is substantially of good purity, capable of being used to product commercial quantities of Nizatidine pharmaceutical grade. Dimethylaminothioacetamide is prepared by reacting dimethylaminoacetonitrile with phosphorus pentasulfide, which is then reacted with 1,3-dichloroacetone in dialkylethers, to get substantially pure 4-chloromethyl-4-hydroxy-2-dimethylaminomethyl-2-thiazoline.
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- Synthesis of thiazoles
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Certain 4-halomethylthiazoles having a 2-substituted-aminomethyl group are prepared by reacting an aminothioamide with a dihalopropanone in the presence of a haloalkane and a bicarbonate, and dehydrating the resulting intermediate.
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