Triazolo-thieno[3,2-e]pyrimidines obtained by cyclisation of 4-hydrazino-2-(methylthio)thieno[2,3-d]pyrimidine with formic acid, acetic acid, cyanogen bromide and carbon disulfide, and by oxidation of the derived aldehyde hydrazones, are found to be the triazolo[4,3-c] isomers. These [4,3-c] compounds resist isomerisation in acid, but they undergo Dimroth rearrangement to the [1,5-c] isomers under
三唑并
噻吩并[3,2-e]
嘧啶通过4-
肼基-
2-(甲硫基)噻吩并[2,3-d]
嘧啶与
甲酸、
乙酸、
溴化氰和
二硫化碳的环化,并通过氧化发现衍生的醛腙是三唑并[4,3-c]异构体。这些 [4,3-c] 化合物在酸中抵抗异构化,但它们在碱性条件下会发生 Dimroth 重排为 [1,5-c] 异构体。一种这样的重排产物,5-甲氧基-8,9,10,11-四氢[1]
苯并噻吩并[3,2-e][1,2,4]三唑并[1,5-c]
嘧啶的晶体结构( X 射线分析证实了图 13b)。