Patent ID: 8242291
Filing Date: 2012-08-14
Classification: C07D,C07F

Abstract:
1. Process for the preparation of N-[2-(8S)-1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan-8-yl]ethyl]propionamide (ramelteon), of formula (I) comprising the following reactions: a) alkylation of the hydroxyl of 6-hydroxy-indanone (compound (II)), to obtain the intermediate (III), 6-allyloxy-indan-1-one: b) thermal Claisen rearrangement on the intermediate (III) to obtain the intermediate (IV), 7-allyl-6-hydroxy-indan-1-one: c) protection of the free hydroxyl of the intermediate (IV) to obtain an intermediate of formula (V): wherein (PG-OH) indicates the hydroxyl group protected with a protective group stable in a basic environment; d) reaction of the intermediate (V) to obtain an intermediate of formula (VI):