公开(公告)号：BR7602622A

公开(公告)日：1976-11-23

申请号：BR7602622

申请日：1976-04-28

Applicant: HOECHST AG

Inventor： SAHM W ,  HILLE E ,  SCHILLER W

IPC: E01B27/04 ,  C07D235/04

公开(公告)号：IN144220B

公开(公告)日：1978-04-08

申请号：IN735CA1976

申请日：1976-04-27

Applicant: HOECHST AG

Inventor： SAHM W ,  SCHILLER W ,  HILLE E

IPC: C07D235/26 ,  C07D49/36

Abstract: 5-Acetoacetylamino benzimidazolone-(2) is obtained in high yield and excellent purity by reacting diketene with the aqueous solution of a salt of 5-amino-benzimidazolone-(2) and an acid having a pKa value of 1 to 7, preferably in the presence of an antioxidant and/or a reducing agent.