8,9-DIHYDROXANTHENE AND METHOD OF PREPARATION THEREOF Russian patent published in 1998 - IPC

FIELD: chemical industry. SUBSTANCE: present invention describes compounds of general formula I wherein is hydrogen atom; R₁ is lower alkyl; R₂ is lower alkyl; R₃ is hydrogen atom; R₄ is hydrogen atom, halogen atom, nitro group or lower alkoxy group; R₅ is hydrogen atom; R₆ is hydrogen atom or allyl; A is group O, R₇ wherein X-is N⁺R₈R₉•X^-; ClO₄ is lower alkyl unsubstituted or substituted by hydroxy group, tolyl, benzoyl, phenyl substituted by lower alkoxy group or lower alkoxycarbonyl group; R₈ is hydrogen atom, lower alkyl or R₉ and R₈ together form R₉; or A is (CH)₂O(CH)₂; wherein NR₈ is tolyl unsubstituted by lower alkoxy group or hydroxyl; phenyl unsubstituted or substituted by halogen; or A is R₈ wherein N⁺R₈R₉•Br^-, is phenyl unsubstituted or substituted by halogen, lower alkoxy group or tolyl. The claimed compounds have high spectral characteristics, high photochemical stability, are resistant to polar and unpolar solvent and useful as fluorescent dyes for dying various textile and non- textile materials in manufacture of inks, pencils and cosmetic agents, signal paints as active media in liquid lasers when excited by various methods. The claimed method of preparing compounds (I) comprises reacting 5,5- substituted 1,3-dialkoxy-1-substituted cyclohexanium salts with 2-hydroxyaraldehyde and subsequently treating the resulting 7-alkoxy-8,9-dihydroxan salt either with amine to prepare compounds of general formula (I) wherein A is R₈, or with water to prepare of general formula (I) wherein A is 0, and optionally, to prepare compounds of general formula (I) wherein A is A = N⁺HR₈•C10-4

,N⁺R₈R₉•ClO-4, compound of general formula (I) wherein A is NR₈ is treated with base, and optionally to prepare 7-imino-8,9-dihydroxanthene salt of general formula (I) wherein A is N⁺HR_a•ClO-4 wherein X-has various meanings as given above, solution of compounds of general formula I, wherein A is N⁺HR_aX^-, is treated with acid, NR_a have meanings as defined above in all cases. Found: N, R₁-R₉, A. Yield (%), T(С), 4V spectrum (R₁,R₂,R₃,R₄,R₅,R₆,R₇,- E, nm): Ia, H, CH₃, CH₃, H, H, H, H, O, 91.0, 181-183; 1b, H, CH₃, CH₃, H, CH₃O, H, H, O, 94.5, 136-137; Ig, H, CH₃, CH₃, H, CH₃O, H, H, N⁺(C₂H₅)₂•C10-4, 67.5-, 271-273; Ii H, CH₃, CH₃, H, CH₃O, H, H, N⁺(C₂H₅)₂•C10-4, 78.3, 208-209; Is, H, CH₃, CH₃, H, CH₃O, H, H, NC₆H₅, 91.0, 179-180, If H, CH₃, CH₃, H, CH₃O, H, H NC₆H₄Br-n, 88,7, 152-153; 1h, H, CH₃, CH₃, H, CH₃O, H, H, N⁺HC₆H₄CH₃-n•Br^- 91.6, 208-210. EFFECT: improved properties of the title compounds. 3 cl, 5 tbl