METHOD OF SYNTHESIS OF AN INTERMEDIATE PRODUCT FOR SYNTHESIS OF THERMOSTABLE POLYIMIDES Russian patent published in 1995 - IPC

FIELD: chemical technology. SUBSTANCE: synthesis of an intermediate product is carried out by reaction of m-carborandicarboxylic acid chloroanhydride with triphenylamine in the medium of o-dichlorobenzene in inert atmosphere followed by treatment with anhydrous AlCl₃ at gradual temperature increase up to 150 C and the following keeping at 140-150 C. Prepared dry solid product is treated with 4-chloroformylphthalic anhydride in the medium of o-dichlorobenzene, reaction mixture is kept and temperature is increased gradually from 50 to 140 C, and the end product is isolated and purified. The yield is 75%, empirical formula is (C₅₈H₄₁B₁₀N₂O₁₀)₂,, neutralization equivalent is 530, molecular mass is 2120 (measured - 2066). Product is insoluble, no melting and consists of dimeric molecule with intermolecular bond. EFFECT: increased yield of product. 2 tbl