反应详情

As in Example 99, a solution of 3,3-bis(3-nitrophenyl)-2-propenal (7.9 g) and (carboethoxymethylene)triphenylphosphorane (9.75 g) in ethanol was stirred at room temperature for 1 hour. The usual work up gave a mixture of esters which was crystallized from dichloromethane-hexane to furnish 6.7 g of (E)-5,5-bis(3-nitrophenyl)-2,4-pentadienoic acid ethyl ester, mp 121°-123° C. Recrystallization from the same solvent gave the analytical sample, mp 122°-123° C. Anal. Calculated for C19H16N2O6 : C, 61.96; H, 4.38; N, 7.60 Found: C, 62.63; H, 4.60; N, 7.79.

1. customThe usual work up gave
2. customwas crystallized from dichloromethane-hexane