2,8-DIMETHYL-3,7-DIALKOXY-5-R-FURO[C;B]TROPYLIUM SALTS AND METHOD FOR THEIR PRODUCTION Russian patent published in 1998 - IPC

FIELD: organic chemistry; production of biologically active compounds. SUBSTANCE: compound having common formula (I) where R is hydrogen atom, styryl, phenyl being unsubstituted or substituted by mono- or dihydroxy, mono- or di(C₁-C₁₀)alkoxy, methyldioxy, di(C₁-C₆)alkylamino, halogen, nitro groups; R₁ is C₂-C₆ alkyl are prepared by interaction of 3,4-diacetylhexane dione with aliphatic or aromatic aldehydes. The process is carried out in the presence of mixture of perchloric acid and acetic acid, it is followed by treatment with trialkyl orthoformates. Compound where R₁=C₂H₅, R = C₂H₅ have essential formula C₂₁H₂₃ClO₇, said compound having melting point 242-243 C is prepared at 80.3 % yield. Compound where R₁= CH₃, R = 4-CH₃OC₈H₄ have essential formula C₂₀H₂₁ClO₈, said compound having melting point 237-238 C is prepared at 78.5 % yield. Compound where R₁=C₂H₅, R = 4-OHC₆H₄ have essential formula C₂₁H₂₃ClO₈, said compound having melting point 248-249 C is prepared at 85.0 % yield. Compound where R₁=C₂H₅, R = 3,4-(OH)₂C₆H₃ have essential formula C₂₁H₂₃ClO₈, said compound having melting point 287-288 C is prepared at 89.4 % yield. Compound where R₁= C₂H₅, R = 4-CH₃OC₈H₄ have essential formula C₂₂H₂₅ClO₈, said compound having melting point 242-243 C is prepared at 76.2 % yield. Infrared spectra of said compounds and their PMR-spectra are given here. Desired compounds have high reaction activity in respect with nucleophiles; these compounds may be used for production of various novel biologically active compounds of furo[c; b]tropylium series. EFFECT: improved quality of desired product; improved efficiency of the method. 3 cl, 6 tbl