DERIVATIVES OF 2-AMINOPYRAZINE-5-CARBOXAMIDE, A METHOD OF THEIR SYNTHESIS AND A DRUG AND A PHARMACEUTICAL COMPOSITION CONTAINING SAID Russian patent published in 1999 - IPC

FIELD: organic chemistry and chemical technology, pharmacy. SUBSTANCE: invention relates to synthesis of compounds showing antagonistic activity with respect to α₁--adrenoreceptors at the level of lower urinary way. Derivatives of 2-aminopyrazine-5-carboxamide of the general formula (I) where n = 0 or 1; R¹ means methyl-group and in this case R² means phenoxy-(C₁-C₄)-alkyl-group where phenoxy-group is substituted in turn with methoxy- or ethoxy-group; or R¹ and R² in combination with nitrogen atom to which they are bound form 4-(phenoxymethyl)piperide-1-yl-group where phenoxy-group is substituted with one or two (C₁-C₄)-alkyl groups, or 4-phenylpiperazine-1-yl-group where phenyl-group is substituted with one or two substituents taken from halogen, methoxy-, ethoxy- or (C₁-C₄)--alkyl-group; R³ means hydrogen atom or methyl-group; R⁴ means hydrogen atom; R⁵ means hydrogen atom or a group of the general formula where R⁶ means hydrogen atom, tert.-butylhydroxycarbonyl-group, 4-carbamoylpyrimidine-2-yl-group or 5-carbamoylpyrazine-2-yl-group in the form of base or acid-additive salt. Invention describes also a method of synthesis of compounds of the formula (I) and drug and a pharmaceutical composition containing compounds of the formula (I) exhibiting the above indicated activity. EFFECT: improved method of synthesis, enhanced effectiveness of compounds. 5 cl, 1 dwg, 2 tbl, 8 ex