Process for the resolution of (.+-.) 2-[2'-(p-fluorophenyl)-5'-benzoxazolyl]-propionic acid

US4698432A · kind A · utility

Assignee

• Ravizza S.p.a. · IT

Inventors

• Alberto Verga · Milano, IT
• Oreste Piccolo
• Ermanno Valoti · Desio, IT

Key dates

• Filing date: Jul 19, 1985
• Grant date: Oct 6, 1987
• Expiry date: Jul 19, 2005

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D263/57
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the resolution of (.+-.) 2-[2'-(p-fluorophenyl)-5'-benzoxazolyl]-propionic acid, indicated for brevity as (.+-.)-FBP, by treatment with (-)N-R-glucamine, indicated for brevity as NRG and in which R is an alkyl or cycloalkyl radical, followed by fractional crystallization of the mixture of the diastereoisomer salts obtained, and by separation of the precipitate, from which, by hydrolysis, (.+-.)-FBP is obtained with the required purity characteristics. The levorotatory antipode, (-)-FBP, is racemized, preferably by the formation of one of its esters, which is then hydrolyzed to give the (.+-.)-FBP, which is recycled to the treatment with NRG. (+)-FBP and (-)-FBP salts with NRG obtained by said process.