METHOD OF PREPARING 1,3-DIMETHYL-4,8-DIALCOXY-6-R-PYRROLO(THIENO)-[C]- TROPILIUM SALTS Russian patent published in 1999 - IPC

FIELD: organic synthesis. SUBSTANCE: compounds of general formula I: (I) wherein Z is S, N-H, N-R (R is C₁-C₁₀-alkyl, C₁-C₁₀-alkoxy, and carbethoxy radicals); R₁ is hydrogen atom, styryl, phenyl, mono- or dihydroxyphenyl, mono- or dihydroxy-C₁-C₁₀-alkoxy, methylenedioxy, and di-C₁-C₆-alkylamino groups; R₂ is C₁-C₁₀=alkyl; and X is ClO₄, HSO₄, or Br; are prepared by heating 3,4-diacetylhexanedione (formula II: (II)) with hydrogen sulfide in acetic acid or by melting it with alkylamines, arylamines, their acetate salts, or ammonium acetate to form 2,5-dimethyl-3,4-diacetylpyrrols(thiophenes), which, in the same reactor or after intermediate isolation from reaction mixture, are brought into interaction with trialkyl-ortho-formiates and inorganic acid (to form compounds I with R₁ = H) or with aromatic aldehydes R₁- CHO in presence of perchloric acid followed by treatment with trialkyl- ortho-formiate (to form compounds I with R₁ = styryl, or optionally substituted phenyl). Compounds I are potential biologically active compounds, which manifest high reactivity in reactions with nucleophils and can be used for production of various known and new biologically active compounds of pyrrolo(thyeno)-[C]-tropilium and azaazulene types. EFFECT: extended choice of biologically active compounds. 7 cl, 2 tbl, 21 ex