A new general approach to a large variety of hitherto hardly accessible 4-unsubstituted and 4-alkyl-substituted 5-acyl-1,2,3,4-tetrahydropyrimidine-2-thiones(ones) has been developed. The approach is based on the reaction of enolates of various 1,3-diketones or β-oxoesters with readily available N-[alkyl(tosyl)methyl]thioureas, N-(azidomethyl)thiourea, and N-[alkyl(tosyl)methyl]ureas followed by TsOH-catalyzed dehydration of the intermediate 4-hydroxyhexahydropyrimidine-2-thiones(ones) without or with isolation of the latter.
我们开发出了一种新的通用方法,可用于制备迄今为止难以获得的大量 4-未取代和 4-烷基取代的 5-酰基-1,2,3,4-四氢
嘧啶-2-亚
硫酰(一)。该方法基于各种 1,3-二酮或β-氧代酯的烯醇化物与容易获得的 N-[烷基(
甲苯基)甲基]
硫脲、N-(
叠氮甲基)
硫脲和 N-[烷基(
甲苯基)甲基]
脲反应,然后在 TsOH 催化下对中间体
4-羟基六氢
嘧啶-2-
硫酮(一)进行脱
水,而不分离或分离后者。