Synthesis of tetrahydropyrimidines with 2-oxoalkyl groups using pyrimidinium salts and enol silyl ethers: formation of diazabicyclo[3.3.1]nona-3,6-diene derivatives
作者:Yohsuke Yamamoto、Akira Sakaguchi、Hiroshi Yoshida、Kin-ya Akiba
DOI:10.1039/p19880000725
日期:——
Reactions of N-silyl- or N-acyl-pyrimidinium salts with enol trimethylsilyl ethers were carried out to afford the adducts with a 2-oxoalkyl group, that is, 2-hydroxy-4-(2-oxoalkyl)-1,2,3,4-tetrahydropyrimidines (9) or the 3-acyl derivatives (8), respectively. Monoacylation of compounds (9) gave monoamides (8) in high yields. Exhaustive acylation of diamines (9) with a large excess of 2,2,2-trichloroethyl
进行N-甲硅烷基-或N-酰基-嘧啶鎓盐与烯醇三甲基甲硅烷基醚的反应,得到具有2-氧代烷基的加合物,即2-羟基-4-(2-氧代烷基)-1,2, 3,4-四氢嘧啶(9)或3-酰基衍生物(8)。化合物(9)的单酰化以高收率得到单酰胺(8)。在吡啶存在下用大量过量的2,2,2-三氯乙基氯甲酸将二胺(9)彻底酰化,得到双环化合物2-oxa-8,9-diazabicyclo [3.3.1] nona-3,6-dienes (14)。通过添加三氟乙酸,化合物(14)被重新打开以提供3,4-二氢嘧啶盐(11 '),将其进行亲核攻击以高收率得到1,2,3,4-四氢嘧啶(16)。