Preparation of 3-(3,4,5,6-tetrahydro-phthalimido)-benzaldehydes

US4937354A · kind A · utility

Assignee

• BASF SE

Inventors

• Klaus Fischer · Speyer, DE
• Lothar Rueb · Speyer, DE
• Peter Plath · Bischofswerda, DE

Key dates

• Filing date: Apr 14, 1989
• Grant date: Jun 26, 1990
• Expiry date: Apr 14, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D319/06
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

3-(3,4,5,6-Tetrahydrophthalimido)-benzaldehydes of the type I ##STR1## or corresponding derivatives substituted in the phenyl ring are prepared by PA1 (a) acetalization of a 3-nitrobenzaldehyde III or of a corresponding derivative with an alcohol IV in the presence of an acidic catalyst to give the corresponding cyclic acetal V ##STR2## (b) reduction of the cyclic acetal V with hydrogen to give the corresponding amino compound II and PA1 (c) subsequent condensation of this aminophenyl acetal II with 3,4,5,6-tetrahydrophthalic anhydride in an acidic reaction medium.