摘要:
2-Amino-5-alkoxycarbonylfurans la-c react with 1-chloro-2,2,2-trihalogenoethyliden-O-methylurethanes 2a,b at room temperature to give N-(2-furyl)-N'-methoxycarbonyl-trihalo-genoacetamidines 3a-f which cyclize into 2-trihalogenomethyl-3,4-dihydrofuro[2,3-d]pyrimidin-4-ones 4a-f on boiling in toluene.