反应详情

A suspension of 0.4 g of the product of Step A in 15 ml of ethanol was refluxed for 2 hours and the resulting clear orange solution was concentrated to half its volume. The mixture was filtered to obtain 0.25 g of ethyl imidazo-[1,2-a]-quinoxaline-2-carboxylate as a pale yellow solid which were crystallized from an ether-methanol mixture to obtain the product in the form of soft-white needles melting at 184°-187° C. with decomposition.

1. temperaturewas refluxed for 2 hours
2. concentrationthe resulting clear orange solution was concentrated to half its volume
3. filtrationThe mixture was filtered