| abstract |
The present invention relates to a preparation method of 7-chloro-5-oxo-2,3,4,5-tetrahydro-1H-1-benzazepine, 7-chloro-5-oxo-2,3 , 4,5-tetrahydro-1H-1-benzazepine is an important intermediate for the preparation of arginine vasopressin V2 receptor antagonist tolvaptan. This preparation method uses 2-amino-5-chlorobenzoic acid methyl ester and 4-bromobutyric acid ethyl ester as starting materials, generates secondary amine under the action of acid-binding agent, and then undergoes Dickmann condensation and hydrolysis reaction to obtain the target Compound 7-Chloro-5-oxo-2,3,4,5-tetrahydro-1H-1-benzazepine. Compared with the existing method, the method has fewer reaction steps, is easy to operate, has good product purity, and greatly improves the yield, thereby reducing production cost and increasing income. |