2.57 g (0.01 mol) of the 4,4'-dimethoxybenzophenone oxime as obtained in (1) was dissolved in 5 ml of dimethylformamide and 1.2 g of potassium tert-butoxide was added thereto under ice cooling. The resulting mixture was stirred for ten minutes. Then 1.8 g of ethyl 4-chloroacetoacetate was added thereto and the obtained mixture was stirred at room temperature. After two hours, the reaction mixture was poured into diluted hydrochloric acid and extracted with ethanol. The crude product thus obtained was purified by silica gel chromatography to give 3.1 g of the title compound.
