Synthesis of [1,3,4]thiadiazolo[3,2-<i>a</i>]pyrimidines in the presence of formic acid
作者:Keiko Takenaka、Tadakazu Tsuji
DOI:10.1002/jhet.5570330459
日期:1996.7
Formic acid-phosphorus pentoxide was effective for the preparation of 5,7-dimethyl[1,3,4]thiadiazolo- and -[1,3]thiazolo[3,2-a]pyrimidin-4-ium salts. Further, the pyrimidine ring transformation and the isocyanation of 5imino-6H-[1,3,4]thiadiazolo- and -[1,3]thiazolo[3,2-a]pyrimidin-7-ones were carried out in the presence of formic acid and triethyl orthoformate, respectively.
甲酸-五氧化二磷对制备5,7-二甲基[1,3,4]噻二唑-和-[1,3]噻唑并[3,2 - a ]嘧啶-4-鎓盐有效。此外,在存在下进行5-亚氨基-6 H- [1,3,4]噻二唑-和-[1,3]噻唑并[3,2 - a ]嘧啶-7-的嘧啶环转化和异氰酸酯化反应。分别是甲酸和原甲酸三乙酯。