Convenient synthesis and characterization of molecules containing multiple β-keto ester units
摘要:
Three compounds containing two beta-keto ester units and one containing three were obtained in good yields from sebacyl, terepthaloyl, isophthaloyl, and trimesoyl chlorides. In this one pot procedure the acid chlorides were first treated with ethyl acetoacetate and barium oxide and then with ethyl alcohol. The aliphatic ester exists mainly as keto ester with a very small amount of the enol tautomer. In the case of aromatic esters, all possible tautomers were found in considerable concentrations in deuterochloroform solution. Theoretical chemical shifts were estimated from GIAO/WP04/aug-cc-pVDZ/SCRF calculations, for a probable signal assignation for the corresponding tautomeric species. Our theoretical results are in agreement with experimental findings and account for negligible stability differences between the tautomers of each aromatic compound. (C) 2012 Elsevier Ltd. All rights reserved.
Three-component condensation of diethyl isophthaloyldiacetate, aromatic aldehyde, and urea as a new method for the synthesis of 1,3-bis(2-oxo-1,2,3,4-tetrahydropyrimidin-6-yl)benzenes
作者:V. A. Mamedov、S. V. Vdovina、E. I. Vorkunova、L. V. Mustakimova、A. F. Saifina、A. T. Gubaidullin、I. Kh. Rizvanov、Ya. A. Levin、I. A. Litvinov
DOI:10.1007/s11172-008-0161-1
日期:2008.6
Condensation of diethyl isophthaloyldiacetate, aromatic aldehyde, and urea in the presence of Me3SiCl proceeds efficiently and faster than in the absence of the latter to form 1,3-bis(2-oxo-1,2,3,4-tetrahydropyrimidin-6-yl)benzene derivatives capable to give inclusion complexes with DMF.
Chloro(trimethyl)silane-catalyzed three-component condensation of diethyl 3,3′-(1,3-phenylene)bis(3-oxo-propanoate) with aromatic aldehyde and urea. New synthesis of diethyl 4,4′-(1,3-phenylene)bis(2-oxo-1,2,3,6-tetrahydropyrimidine-5-carboxylates)