作者:Rodney L. Willer、Robson F. Storey、Christopher G. Campbell、Steven W. Bunte、Damon Parrish
DOI:10.1002/jhet.1054
日期:2012.7
to give a good yield of [1,2,5]thiadiazolo[3,4‐b]pyrazine, whereas the oxadiazole had not yielded, until now, [1,2,5]oxadiazolo[3,4‐b]pyrazine (or furazano[2,3‐b]pyrazine). The calculations suggested that the diols, 5,6‐dihydroxy‐4,5,6,7‐tetrahydro[1,2,5]oxadiazolo[3,4‐b]pyrazine and 5,6‐dihydroxy‐4,5,6,7‐tetrahydro[1,2,5]thiadiazolo[3,4‐b]pyrazine should be stable intermediates, and once formed, should
反应坐标图用于研究3,4-二氨基[1,2,5]恶二唑(3,4-二氨基呋喃山)和3,4-二氨基[1,2,5]噻二唑与乙二醛的反应。已知噻二唑的[1,2,5]噻二唑[3,4- b ]吡嗪的收率很高,而恶二唑直到现在还没有[1,2,5]恶二唑[3,4- b ]吡嗪(或呋喃并[2,3- b ]吡嗪)。计算建议二醇,5,6-二羟基-4,5,6,7-四氢[1,2,5]恶二唑并[3,4- b ]吡嗪和5,6-二羟基-4,5,6- ,7-四氢[1,2,5]噻二唑并[3,4- b ]吡嗪应该是稳定的中间体,和一旦形成,应该提供一个途径,以目标化合物通过在强制条件下,执行两个脱水步骤。考虑到这些信息,重新检查了3,4-二氨基[1,2,5]恶二唑与乙二醛和丙酮醛的反应。3,4-二氨基[1,2,5]恶二唑与乙二醛和丙酮醛的反应在碱性条件下产生了接近定量的预期初始产物5,6-二羟基-4,5,6, 7-四氢[1,2,5]恶二唑[3