2-Chloroaniline → 2-p-Tolylbenzoxazole

Participants

Reaction Steps

4.2 g (0.02 mole) of 2-(p-tolyl)-benzoxazole of the formula ##STR48## and 6.7 g (0.02 mole) of the Schiff's base, obtained from 2-phenyl-6-formyl-benzoxazole and o-chloroaniline, of the formula ##STR49## (melting point: 112.5°-113.5° C.) are dissolved in 80 ml of dimethyl formamide. To this solution are added in small amounts in the course of 20 minutes 2.1 g (0.002 mole) of sodium tert.butylate at 20° to 25° C. while introducing nitrogen. During the first 10 minutes, the reaction mixture is irradiated with ultraviolet light. While further introducing nitrogen and stirring for 2 hours at 20° to 25° C. the colour of the mixture changes gradually from yellow through violet brown to brown. Then 320 ml of methanol are added and the batch is cooled to 0° C. The precipitate is collected by filtration, washed repeatedly with a total of 40 ml of methanol and dried, affording 3.2 g (39% of theory) of 1-(2-phenyl-benzoxazol-6-yl)-2-(4'-benzoxazol-2-yl-phenyl)-ethylene of the formula ##STR50## in the form of a light beige-coloured powder with a melting point of 233°-237° C.

Provenance & Evidence