Water → 5-Chloro-2-{4-[2-(2-phenyl-1,3-benzoxazol-6-yl)ethenyl]phenyl}-1,3-benzoxazole

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Reaction Steps

A solution of 4.46 g (0.02 mole) of 2-phenyl-6-formyl-benzoxazole of the formula ##STR29## (melting point: 133°-135° C.) and 7.59 g (0.02 mole) of 2-(p-diethylphosphonomethylphenyl)-5-chloro-benzoxazole of the formula ##STR30## (melting point: 96°-98°) in 80 ml of dimethyl formamide is heated to 40° C. Then 2.1 g (0.022 mole) of sodium tert.butylate are added in small amounts to the solution over the course of 30 minutes and the resultant suspension is further stirred for 4 hours at 40° C. The reaction mixture is poured into water and the precipitate is collected by filtration, washed with water and subsequently with a total amount of 110 ml of methanol. The product is recrystallised form a solvent mixture of nonane/xylene (1:1) with the addition of fuller's earth, affording 3 g (30% of theory) of 1-(2-phenylbenzoxazol-6-yl)-2-[4'-(5-chlorbenzoxazol-2-yl)-phenyl]-ethylene of the formula ##STR31## in the form of pale yellow flakes having a melting point of 241°-242° C.

Provenance & Evidence