FIELD: organic chemistry, chemical technology, biochemistry, pharmacy.
SUBSTANCE: invention relates to methods for preparing 2-phenylamino-5-alkylphenylacetic acids of the general formula (I) 
intermediate compounds for their preparing, their pharmaceutically acceptable salts and pharmaceutically acceptable prodrug esters wherein R, R1, R2, R3, R4 and R5 have corresponding values. Compound of the general formula (I) is prepared by splitting lactam of the formula (II): 
wherein symbols have values given in the description with a base, its precursors and methods for preparing these precursors. Abovementioned methods can comprise if necessary the temporal protection of all reaction groups showing effect followed by isolation of the prepared compound. Invention provides preparing compounds of the general formula (I) representing pharmaceutically active compounds that represent selective inhibitors of cyclooxygenase-2.
EFFECT: improved preparing method, valuable biochemical properties of compounds.
10 cl, 1 sch, 9 ex
