反应详情

Triethylamine (9.87 ml) was added dropwise, over a period of 1 hour to a cooled (ice bath) solution of ethyl 4-chloroacetoacetate (9.87 g, 60 mmol) and ethyl p-isocyanatobenzoate (14.34 g, 75 mmol) in 60 ml of petroleum ether-ethyl acetate (10:1 by volume), under nitrogen atmosphere. The reaction mixture was stirred at 0°-5° C. for 1 hour. The resulting ethyl 2-[[4-(ethoxycarbonyl)phenyl]-amino]-4,5-dihydro-4-oxo-3-furancarboxylate was filtered and then washed sequentially with petroleum ether, 1 N hydrochloric acid and water. Yield 13.0 g Mp 152°-153° C. (isopropanol).

1. filtrationThe resulting ethyl 2-[[4-(ethoxycarbonyl)phenyl]-amino]-4,5-dihydro-4-oxo-3-furancarboxylate was filtered
2. washwashed sequentially with petroleum ether, 1 N hydrochloric acid and water