METHOD OF SYNTHESIS OF COMPOUNDS OF GROUP IMIDAZO-[1,2-B]-PYRIDAZINE OR THEIR SALT Russian patent published in 1995 - IPC

FIELD: organic chemistry. SUBSTANCE: products: imidazo-[1,2-b]-pyridazines of the formula (I) where R₁ - hydrogen or halogen atom; R₂ and R₃ are independently - hydrogen, lower alkyl which does not obligatory substituted with hydroxyl, naphthyl, substituted with lower alkyl, pyrrol, pyridine, C₃-C₆-cycloalkyl, phenyl which can be substituted with halogens or lower alkoxy-groups, or R₂ and R₃ together with nitrogen atom with which they were bound form piperidine, piperazine or morpholine ring. In the case of piperazine ring the latter can be substituted with lower alkyl, phenyl, (lower) alkyl, pyridine, pyrimidine or benzdioxalane; X - O or S, Alk-alkylene group with direct or branched chain containing 1-5 carbon atoms and does not obligatory substituted with phenyl. At condition that X - O when R₁ - H or halogen then one of R₂ and R₃ or lower alkyl group, and Alk-alkylene group with direct or branched chain containing 2-5 carbon atoms. Reagent 1: compound of the formula (II) or its salt where R₁ and X are indicated above. Reagent 2: YAlkSO₂NR₂R₃ where R₂ and R₃ and Alk are indicated above, and Y - reactive group or its salt. Reaction condition: in inert solvent, and the end product is isolated in free form or as a salt. EFFECT: improved method of synthesis.