531-91-9

GREY TO BROWNISH FINE CRYSTALLINE POWDER

See diphenylamine.

The synthesis of N,N'-Diphenylbenzidine is as follows:
3.12 g (10mmol) of 4,4'-dibromodiphenyl, 2.3 mL (25 mmol) of aniline, 2.9 g (30 mmol) of t-BuONa, 183 mg (0.2 mmol) of Pd2(dba)3, and 20 mg (0.1 mmol) of P(t-Bu)3 were dissolved in 30 mL of toluene, and then stirred at 90°C for 3 hrs. The reaction mixture was cooled to room temperature and three times extracted with distilled water and diethyl ether. Precipitates in an organic layer were filtered, washed with acetone and diethyl ether, and then dried in vacuum to obtain 0.3g of the intermediate compound C (yield: 90%). 

Crystallise the benzidine from toluene or ethyl acetate. Store it in the dark. [Beilstein 13 H 223, 13 IV 368.]