Construction of a dihydropyrimidine ring was developed that involved the cyclization of 1,3-diaza-1,3-butadienes having an N-protecting group (N-Cbz, N-Boc, N-alkyl, or N-benzyl) with α,β-unsaturated carbonyl compounds such as ethyl acrylate and p-chlorophenyl vinyl ketone. Consequently, 4-dimethylamino-2-phenyl-1,4,5,6-tetrahydropyrimidines were synthesized in good yields. Subsequently, the β-elimination
开发了二氢
嘧啶环,该环涉及将具有N-保护基(N -Cbz,N -Boc,N-烷基或N-苄基)的1,3-二氮杂
1,3-丁二烯与α进行环化, β-不饱和羰基化合物,例如
丙烯酸乙酯和对
氯苯基
乙烯基酮。因此,以良好的产率合成了4-二甲基
氨基-2-苯基-1,4,5,6-四氢
嘧啶。随后,用MeI或SiO 2进行二甲基
氨基的β-消除。得到高产率的各种N-保护性2,5-二取代-1,6-二氢
嘧啶。显着地,使用4-
氯苯基
乙烯基酮直接提供了二氢
嘧啶,而没有四氢
嘧啶中间体,产率很高。