METHOD OF PREPARING 2-BUTYL-3-[(2'-TETRAZOL-5-YL)BIPHENYL-4-YL)METHYL]-1,3- DIAZASPIRO[4,4]NON-1-EN-4-ONE IN A OR B FORM, METHOD OF PREPARING B FORM, B FORM, AND PHARMACEUTICAL COMPOSITION BASED ON B FORM Russian patent published in 2000 - IPC

FIELD: synthesis of biologically-active compounds. SUBSTANCE: method consists in (i) treating 2-butyl-3-[(2'-cyanobiphenyl-4-yl)methyl]-1,3- diazaspiro[4,4] non-1-en-4-one with alkali metal azide and triethylamine hydrochloride in aprotic polar inert solvent and isolating resultant 2- butyl-3-[(2'-tetrazol-5-yl)biphenyl-4-yl)methyl] -1,3-diazaspiro[4,4]non- 1-en-4-one in the form of one of its alkali metal salts in aqueous solution; (ii) neutralizing above-indicated salt solution to pH 4.7-5.3; and (iii) crystallizing precipitated product either in solvent containing less than 10% water to isolate product in A form: (A), or in water-miscible solvent containing more than 10% water to isolate product in B form: (B) showing specific X-ray diffraction pattern on powder. B form- containing composition is characterized by antagonistic activity with respect to angiotension receptors. EFFECT: improved preparation procedure. 7 cl, 5 dwg, 11 tbl