Process for the manufacture of 4H-imidazo1,5-A!1,4!benzodiazepines

US5693795A · kind A · utility

Assignee

• Hoffmann-La Roche Inc. · US

Inventors

• Karl-Heinz Bender · Zetel, DE
• Manfred Breuninger · Glückstadt, DE
• Manfred Froom · Glückstadt, DE
• Siegfried Schmitt · Reinach, CH
• Kurt Steiner · Sursee, CH

Key dates

• Filing date: Oct 2, 1996
• Grant date: Dec 2, 1997
• Expiry date: Oct 2, 2016

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61P25/20
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

A process for the manufacture of 4H-imidazo1,5-a!1,4!benzodiazepine derivatives of formula I ##STR1## wherein R.sup.1 is phenyl or mono- or disubstituted phenyl; PA1 R.sup.2 is hydrogen, halogen, nitro, cyano, trifluoromethyl or lower alkyl; PA1 R.sup.3 is hydrogen or lower alkyl; and PA1 R.sup.4 is hydrogen or lower alkyl and of pharmaceutically usable salts of these compounds by decarboxylating a 4H-imidazo1,5-a!1,4!benzodiazepinecarboxylic acid of formula II ##STR2## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 have the above significances, at elevated temperature and under elevated pressure in the presence of an organic solvent. The compounds of formula I and their pharmaceutically usable acid addition salts are known muscle relaxants, sedatives and anticonvulsants.