NON-STERIODAL ANTIINFLAMMATORY DRUGS .3. STRUCTURE OF INDOPROFEN - 2-[4-(1-OXO-2-ISOINDOLINYL)PHENYL]PROPIONIC ACID

Indoprofen, -1-oxo-2H-isoindol-2-yl)-alpha-methylbenzeneacetic acid, C 17H15NO3, a non-steroidal anti-inflammatory agent, falls into the clas s of phenylpropionic acids that includes ibuprofen, ketoprofen and flu birprofen. It adopts a planar conformation apart from the carboxylic a cid group. There is a small twist of 8.8 (2)-degrees between the mean planes of the isoindolinyl and phenyl rings. The rotation of the carbo xyl group out of the plane of the adjacent phenyl ring seems to be con nected with anti-inflammatory activity and is similar to that found in other 2-phenylpropionic acids. A pair of intermolecular hydrogen bond s connects two carboxylic acid groups across a centre of symmetry with an O...O distance of 2.61 (1) angstrom.