FIELD: medicine. SUBSTANCE: product of the general formula (I) 
where R1 - hydrogen, C1-C6-alkyl and C1-C6-alkoxy; every R2 - hydrogen, C1-C6-alkyl, halogen, nitro- or carboxy-group; R3 - heterocycle, amino-group, monosubstituted amino-group and also disubstituted amino-group; A and B every - C1-C6-alkylene; X means NH= or -CH2-; n = 1, 2 or 3, or their pharmaceutically acceptable salts or esters used as an agent decreasing intraocular pressure. EFFECT: improved method of synthesis.
