BENZOCYCLOALKENECARBOXYLIC ACID AND PROCESS FOR ITS PREPN

• Main Authors: HANSJURG WETTER, ANDREAS VON SPRECHER
• Format: Patent
• Language: English
• Published: 09.10.1991
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; APPARATUS THEREFOR; CHEMISTRY; GENERAL METHODS OF ORGANIC CHEMISTRY; HUMAN NECESSITIES; HYGIENE; MEDICAL OR VETERINARY SCIENCE; METALLURGY; ORGANIC CHEMISTRY; PREPARATIONS FOR MEDICAL, DENTAL, OR TOILET PURPOSES; SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS ORMEDICINAL PREPARATIONS

PCT No. PCT/CH91/00064 Sec. 371 Date Nov. 20, 1991 Sec. 102(e) Date Nov. 20, 1991 PCT Filed Mar. 19, 1991 PCT Pub. No. WO91/14671 PCT Pub. Date Oct. 3, 1991.The novel (S)-4-(2-bromobenzoyl)-5-hydroxy-benzocyclobutene-1-carboxylic i.e. the compound of the formula (I) in free form or in salt form, can be used as active ingredient in pharmaceutical preparations and can be prepared by a novel process, which is characterized in that racemic 4-(2-bromobenzoyl)-5-hydroxy-benzocyclobutene-1-carboxylic acid is reacted at elevated temperature with at least the equimolar amount of quinine in an alcoholic solvent for from approximately 6 to approximately 48 hours, the quinine salt of the (S)-4-(2-bromobenzoyl)-5-hydroxy-benzocyclobutene-1-carboxylic acid, precipitated in crystalline form as the direct reaction product, is separated from the reaction mixture, and the (S)-4-(2-bromobenzoyl)-5-hydroxy-benzocyclobutene-1-carboxylic acid is set free from this salt by acid treatment in a customary manner, and, if desired, this free acid is converted into a salt.