METHOD FOR SYNTHESIS OF 4,4'-BIS(3-AMINOPHENOXY)BIPHENYL Russian patent published in 2022 - IPC C07C213/00 C07C217/90 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method for synthesis of 4,4'-bis(3-aminophenoxy)biphenyl, which is used for the production of polyimides having high operational characteristics. The method includes nucleophilic substitution of a meta-located nitro group in 1,3-dinitrobenzene in interaction with 4,4'-dihydroxybiphenyl in N-methylpyrrolidone (NMP) in the presence of K₂CO₃, and reduction of 4,4'-bis(3-nitrophenoxy)biphenyl. Nucleophilic substitution is carried out under action of ultrasound for 3 h, at a temperature of 190°C, and a molar ratio of 1,3-dinitrobenzene : 4,4'-dihydroxybiphenyl = 2:1. Reduction is carried out in ethoxyethanol with 15% solution of TiCl₃, in 10% HCl, at a temperature of 90°C, for 0.1 h, and a molar ratio of dinitro-substrate : TiCl₃ equal to 1:14.

EFFECT: proposed method allows for reduction in time of reactions of aromatic nucleophilic substitution and reduction, as well as an increase in the yield of a diamino product.

1 cl, 2 ex