摘要
3-(Pyrazol-5'-yl)coumarin (3) was prepared from condensation of 3-(2'-formyl-1'-chlorovinyl)-coumarin (1) with hydrazine hydrate at room temperature, followed by cyclization with base. Salicylaldazine was prepared from methoxylation of 1 to give acetal 7, followed by condensation of 7 with hydrazine hydrate at 80℃. Treatment of acetal 7 with thiourea yielded the corresponding 4-substituted-2-thioxo-2H-pyrimidine [ 3, 4-b]-coumarin (12).
3-(Pyrazol-5'-yl)coumarin (3) was prepared from condensation of 3-(2'-formyl-1'-chlorovinyl)-coumarin (1) with hydrazine hydrate at room temperature, followed by cyclization with base. Salicylaldazine was prepared from methoxylation of 1 to give acetal 7, followed by condensation of 7 with hydrazine hydrate at 80℃. Treatment of acetal 7 with thiourea yielded the corresponding 4-substituted-2-thioxo-2H-pyrimidine [ 3, 4-b]-coumarin (12).
