Provided is an improvement method of a preparation technique of 3-(2,2,2-trimethylhydrazine)
propionate dihydrate. The 3-(2,2,2-trimethylhydrazine)
propionate dihydrate is a
drug for a cardiovasculardisease and is a product after
basic hydrolysis and acidification of an intermediate 3-(2,2,2-trimethylhydrazine)
methyl propionate salt (CH3)3N<+>NHCH2CH2COOCH3X<-> (wherein X represents Cl<->, Br<->, I<-> and CH3SO4<->). Due to the fact that the acidification purification process adopted after
hydrolysis is complicated, no better process for solving the problem has been provided so far. According to the method, mixed liquor for acidification is added before and after acidification, the complex (emulsible) or
double salt of 3-(2,2,2-trimethylhydrazine)
propionate dihydrate is not produced, and the steps of
electrodialysis, separation and purification are omitted. Besides, another novel acid agent is added, a high-purity product can be further obtained, and the advantages of
commercial scale production, cost reduction, simple equipment and the like are achieved.