公开(公告)号：DE2155545A1

公开(公告)日：1973-05-17

申请号：DE2155545

申请日：1971-11-09

Applicant: BASF AG

Inventor： RUECHARDT CHRISTOPF PROF DR ,  HASSMANN VOLKER DIPL CHEM ,  QUADBECK-SEEGER HANSJUERGEN DR ,  ARMBRUST HERBERT

IPC: C07D231/56 ,  C07D249/10 ,  C07D49/02

Abstract: Indazoles of formula (I): (where each R1 (same or different) is H, an aliphatic, cycloaliphatic or aromatic residue, or halogen, and R2 is H or an aliphatic residue), which are starting materials for dyes, pharmaceuticals and pesticides, are prepd. by (a) reacting o-toluidines of formula (II) with alkyl nitrite and/or nitrous gases in the presence of acetic anhydride, an alkali salts of a lower alkanoic acid and an inert organic solvent, and (b) removing the acetyl group from the resulting l-acetyl-indazole in a conventional manner. The process is simple and economical, is suitable for industrial use, and gives (I) in better yields and purity than by known processes.