CARBOXYLIC ACID DERIVATIVES Russian patent published in 2001 - IPC

FIELD: chemical industry. SUBSTANCE: described are new carboxylic acid derivatives of formula I: wherein R¹ is carboxy or residue hydrolazable into COOH; R² and R³ are the same or different and are phenyl which is optionally substituted by one or more residues from group consisting of alkyl having 1 to 4 carbon atoms and alkoxyl having 1 to 4 carbon atoms which are bonded in ortho-position through direct bond, methylene and ethylene: R⁴ is phenyl which is substituted by one or more residues from group consisting of alkyl having 1 to 4 carbon atoms, benzyloxy; or napthyl, methylenedioxy phenyl which is substituted by alkoxy having 1 to 4 carbon atoms, ethylenedioxy phenil; R⁵ is alkyl having 1-8 carbon atoms. EFFECT: new carboxylic acid derivatives. 13 ex, 1 tbl