Condensation of 5-Acetyl-3,4-dihydropyrimidin-2(1H)-ones with Hydrazine
摘要:
3,4-Dihydropyrimidines obtained by the Biginelli reaction react with hydrazine to give a mixture of N-[(3,5-dimethyl-1H-pyrazol-4-yl)(R)methyl]ureas and 4-R-3,7a-dimethyl-1,3a,4,5,7,7a-hexahydro-6H-pyrazolo[3,4-d]pyrimidin-6-ones. The latter transform into N-[(3,5-dimethyl-1H-pyrazol-4-yl)(R)methyl]ureas in an acidic medium.
Abstract A series of new pyrimidine and quinazoline derivatives was synthesized by a Biginelli-like reaction of urea/thiourea, aldehyde, and ketone in the presence of hydrochloric acid as a catalyst. In a similar way, some novel diazatricyclo derivatives were obtained via a Biginelli-like reaction followed by an intramolecular Michael-type addition. The yields of products were reasonable after recrystallization
摘要 以尿素/硫脲、醛、酮为原料,以盐酸为催化剂,通过类Biginelli反应合成了一系列新的嘧啶和喹唑啉衍生物。以类似的方式,通过类 Biginelli 反应和分子内迈克尔型加成获得了一些新的二氮杂三环衍生物。乙醇重结晶后产物收率合理。所有新合成的化合物均使用 IR 和 NMR(1H 和 13C)光谱和元素分析进行表征。研究了这些化合物对金黄色葡萄球菌(RTCC,1885)和大肠杆菌(ATCC,35922)的抗菌活性。补充材料可用于本文。转至出版商的在线版磷、硫、和硅和相关元素查看免费的补充文件。图形概要
Synthesis of fused dihydro-pyrimido[4,3-d]coumarins using Biginelli multicomponent reaction as key step
作者:Mihaela Matache、Cristian Dobrota、Niculina D. Bogdan、Ioana Dumitru、Lavinia L. Ruta、Codruta C. Paraschivescu、Ileana C. Farcasanu、Ion Baciu、Daniel P. Funeriu
DOI:10.1016/j.tet.2009.05.088
日期:2009.8
A new efficient approach for the synthesis of functionalized dihydro-pyrimido[4,3-d]coumarins is described. Use of benzyl- or tert-butyl acetoacetate and various salicyl aldehydes in typical Biginelli multicomponent reactions provides esters that can be easily deprotected to yield the corresponding hydroxy acids. Annelation of the latter leads to the target dihydro-pyrimido[4,3-d]coumarins. Formation of some unexpected oxo-bridged tetrahydro-pyrimidines is also described. Spectral properties of the synthesized dihydro-pyrimido[4,3-d]coumarins indicate the necessity to revisit some compounds previously reported as products of direct one-pot Biginelli condensation involving 4-hydroxycoumarin as dicarbonyl component. (C) 2009 Elsevier Ltd. All rights reserved.