Patent ID: 6747153
Filing Date: 2004-06-08
Classification: C07D

Abstract:
A process for preparing tropenol (I): optionally in the form of an acid addition salt thereof, said process comprising:reacting a compound of formula (II) whereinR denotes a group selected from C1-C4-alkyl, C2-C6-alkenyl and C1-C4-alkylene-phenyl, each of which may be substituted by hydroxy or C1-C4-alkoxy, optionally in the form of an acid addition salt thereof or a hydrate thereof, in a suitable solvent with a formamide-acetal of formula (III) â€ƒwherein Râ€² denotes C1-C4-alkyl and Râ€³ denotes a group selected from C1-C4-alkyl and C1-C4-alkylene-phenyl, to obtain a compound of formula IV â€ƒwherein R and Râ€³ are as defined above; decarboxylating the compound of formula (IV) to obtain an ester of formula (V) â€ƒwherein R is as defined above; and saponifying the compound of formula (V) to obtain the compound of formula (I), which is optionally converted into an acid addition salt thereof by reaction with a suitable acid.