反应详情

A solution of 1 g of the product of Step A, 1 g of ethyl bromopyruvate and 50 ml of dimethylethane was stirred at room temperature for 5 days and the mixture was filtered to recover 0.51 g of a white crystalline solid. The latter was chromatographed over silica gel and was eluted with chloroform to obtain 0.15 g of ethyl 4-ethoxy-7,8-dichloroimidazo-[1,2-a]-quinoxaline-2-carboxylate in the form of a white crystalline solid melting at 256°-258° C.

1. filtrationthe mixture was filtered
2. customto recover 0.51 g of a white crystalline solid
3. customThe latter was chromatographed over silica gel
4. washwas eluted with chloroform