4-(2-phenylethenyl)-N,N-bis(p-methylphenyl)-benzenamine

4-(2-phenylethenyl)-N,N-bis(p-methylphenyl)benzenamine and 4-(2,2-biphenylethenyl)-N,N-bis(p-methylphenyl)benzenamine were two excellent performance styryl-substituted triarylamines hole transport material, but its synthesis process was complex and yield was low. Therefore, the synthesis of triarylamine above mentioned was studied in this paper.The process of preparing 4-(2-phenyleth-enyl)-N,N-bis(p-methylphenyl)benzen amine by Buchwald-Hartwig coupling reaction,Wilsmeier-Haach reaction and Wittig-Horner reation which prepared from 4-methyldiphenylamine, parabromo- toluene, benzylchlorideand diphenylbromomethane was studied in this article.The results showed that the optimal reaction condition of N,N-bis(p-methylphenyl aniline) which prepared from 4-methyldiphenylamine and parabromotoluene by Buchwald-Hartwig coupling reaction was as follows: the mole ratio of 4-methyl diphenylamine, parabromotoluene, sodium tert-butoxide, palladiumacetate and tri-tert-butylphosphine was 1:1:1.11:5.11×10-4:8.22×10-3, reaction temperature was 140℃ and reaction time was 2h. Under the above condition,the yield and purity of N,N-bis(p-methylphenyl aniline) were 95.58% and 99.28%.The optimal reaction condition of N,N-bis(p-methylphenyl)benzaldehyde by Wilsmeier-Haach reaction showed that:the mole ratio of phosphorus oxychloride,DMF and N,N-bis(p-methylphenylaniline was 2.48:1.48, reaction temperature was 40℃ and reaction time was 3h. The yield and purity of N,N-bis(p-methylp henyl)benzaldehydewere under the above condition were 87.17% and 98.28%.The optimal reaction condition of diethyl benzylphosphonate which prepared from triethylphosphite and benzylchloride was as followed: the mole ratio of triethylphosphite and benzylchloride was 3.56:1,reaction temperature was 170℃ and reactiontime was 4h.The yield and purity of N,N-bis(p-methylphenyl aniline)under the above condition were 92.97% and 93.96%. The optimal reaction condition of 4-(2-phenylethenyl)-N,N-bis(p-methylphenyl)benzenamine by WittigHorner reation prepared from N,N-bis(p-methylphenyl)benzaldehyde showed that: the mole ratio of diethyl benzylphosphonate, sodium tert-butoxide, DMF, and N,N-bis(p-methylphenyl)benzaldehyde was 2.52:3.03:12.9:1, reaction temperature was 20℃ and reactiontime was 4h.The yield and purity of 4-(2-phenylethenyl)-N,N-bis(p-methylphenyl)benzenaminewere under the above condition were 85.04% and 97.35%. This above synthetic route of preparing 4-(2-phenylethenyl)-N,N-bis(p-methylphenyl)benzenamine has advantages of brief reactions steps, milder conditions, high yield and purity.Due to the steric and electronic effect of diphenylbromomethane, it was very difficult to synthesize ylidediethyl diphenylphosphonate which prepared from triethylphosphite and diphenylbromomethane. Therefore, 4-(2,2-biphenylethenyl)-N,N-bis(p-methylphenyl)benzenamine was not synthesized in this paper.