Synthesis of 4-unsubstituted dihydropyrimidines. Nucleophilic substitution at position-2 of dihydropyrimidines
Synthesis of 4-unsubstituted dihydropyrimidines. Nucleophilic substitution at position-2 of dihydropyrimidines
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DOI：
10.1016/j.tet.2011.01.092
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发表时间：
2011-04-08
期刊：
影响因子：
2.1
通讯作者：
Yamaguchi, Masahiko
中科院分区：
文献类型：
--
作者：
Cho, Hidetsura;Nishimura, Yoshio;Yamaguchi, Masahiko
合成了新型4-未取代的二氢嘧啶类化合物。随后，由于DP骨架的3位上的区域选择性烷氧基羰基化，通过活化2位，以优异的产率获得了在2位上具有氨基部分的各种4-未取代的1，4（3，4）-DP。用苯肼代替胺得到3-氧代-2-苯基-2，3，5，8-四氢[1，2，4]三唑并[4，3-a]嘧啶。根据温度和浓度，在一种衍生物的H-1 NMR光谱中观察到1，4（3，4）-DP的个别互变异构体。另一方面，只有1，4-DP被发现在固态的单晶X-射线晶体学。(C)2011爱思唯尔有限公司保留所有权利。
Synthesis of novel 4-unsubstituted dihydropyrimidines (DPs) was performed. Subsequently, a variety of 4-unsubstituted 1,4(3,4)-DPs with amino moieties at position-2 were obtained in excellent yields by activation of position-2 owing to regioselective alkoxycarbonylation at position-3 of the DP skeleton. 3-Oxo-2-phenyl-2,3,5,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrimidine was obtained using phenylhydrazine instead of amines. Individual tautomers of 1,4(3,4)-DP were observed in the H-1 NMR spectra of one derivative depending on temperature and concentration. On the other hand, only 1,4-DP was found in the solid state by single-crystal X-ray crystallography. (C) 2011 Elsevier Ltd. All rights reserved.