Synthesis and mechanism of formation of 5-benzylidene-2-thioxo-2,3-dihydro-(1H,5H)-pyrimidine-4,6-diones difluoromethoxy derivatives
摘要:
Reactions of 5-benzylidene-2-thioxo-2,3-dihydro-(1H,5H)-pyrimidine-4,6-diones with a singlet difluorocarbene afford difluoromethoxy derivatives in 20-34% yield. The quantum-chemical analysis of the reaction mechanism showed that N,N-dimethylformamide is involved into the formation of difluoromethoxy derivatives.
Synthesis of barbiturate-based methionine aminopeptidase-1 inhibitors
作者:Manas K. Haldar、Michael D. Scott、Nitesh Sule、D.K. Srivastava、Sanku Mallik
DOI:10.1016/j.bmcl.2008.02.066
日期:2008.4
The syntheses of a new class of barbiturate-based inhibitors for human and Escherichia Coli methionine aminopeptidase-1 (MetAP-1) are described. Some of the synthesized inhibitors show selective inhibition of the human enzyme with high potency. (C) 2008 Elsevier Ltd. All rights reserved.
Features of the synthesis of thiobarbituric acid arylidene derivatives in the presence of triethylamine
作者:A. I. Rahimov、S. A. Avdeev
DOI:10.1134/s1070363209110218
日期:2009.11
The synthesis of thiobarbituric acid arylidene derivatives proceeds in two steps, which include 5-(2-hydroxy-2-phenyl)ethyl derivative formation and dehydration. The triethylamine promotes increase in the negative charge on the 5th carbon atom (from -0.399 to -0.638) and positive charge on the aldehyde CH=O group carbon atom (from 0.288 to 0.300) in the transition state due to associative interaction (analysis by quantum-chemical method AM1), and it also promotes dehydration by "pushing out" the hydroxy group. The yield of thiobarbituric acid arylidene derivatives reaches 92-99%.
S-benzylation of arylidene thiobarbituric acids under phase-transfer catalysis