METHOD OF PRODUCING PHENYLALANINE DERIVATIVES WITH QUINAZOLINEDIONE SKELETON AND INTERMEDIATE COMPOUNDS USED TO PRODUCE SAID COMPOUNDS Russian patent published in 2012 - IPC C07D239/96 C07C233/51 C07C237/40 C07C265/12 C07C271/22 C07C275/42 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing phenylalanine with a quinazolinedione ring of formula (1) or a pharmaceutically acceptable salt thereof, which can be used to produce a medicinal agent for treating inflammatory diseases whose pathology involves an α-4-integrin-dependent adhesion process, such as arthritis, inflammatory enteritis,multiple sclerosis etc. In formula (1), R1 is a phenyl group which can contain a substitute; R2 is an alkyl group which can contain a substitute; R3 is an alkyl group which is substituted with a dialkylamino group, an alkyl group which is substituted with a monoalkylamino group or an alkyl group which is substituted with an amino group; and R4 is a hydrogen atom, an alkyl group or a benzyl group which can contain a substitute. The method involves the following steps: (a) reaction of an acylphenylalanine derivative of formula (2), (3), with a reactant which introduces a carbonyl group or an anthranilic acid derivative of formula (3), where R1 and R2 have values given above, and R3' has values R3 which can have a protective group to form a urea derivative with asymmetrically lying carboxy group of formula (4), or a chemically acceptable salt thereof: (4), (5), (b) converting the urea derivative with asymmetrically lying carboxy groups of formula (4) to a quinazolinedione derivative of formula (5), or a pharmaceutically acceptable salt thereof, in the presence of an agent which activates the carboxyl group, where R1-R3' assume the same values given above; and (c) subsequent N alkylation of the compound of formula (5) and removing the protective group if necessary. The invention also relates to novel intermediate products.

EFFECT: method simplifies the process by cutting the number of steps and enables to obtain products with high output.

9 cl, 22 ex