<i>N</i>-[[(Chlorosulfinyl)oxy]methylene]-<i>N</i>-methylmethanaminium Chloride as A Dehydrating Agent. A Direct and Efficient One-Pot Synthesis of Various Pyrimidinones, Azetidinones and Pyridones via Cycloaddition Reactions
作者:Satyendra P. Singh、Asha R. Mahajan、Dipak Prajapati、Jagir S. Sandhu
DOI:10.1055/s-1991-26639
日期:——
N-[[(Chlorosulfinyl)oxy]methylene]-N-methylmethanaminium chloride (1) is found to be an efficient and mild dehydrating agent for the in situ generation of monophenyl- (4a) diphenyl- (4b) and monochloroketenes (4c) directly from the corresponding carboxylic acids 2. These ketenes undergo cycloaddition reactions with 1,3-diaza-1, 3-butadienes 5 to afford 4(3H)-pyrimidinones 6 and azetidones 7, and with 3-(aryliminomethyl)chromones 8 to give [1]benzopyrano[3,2-c]pyridine-3,10[2H]diones 9.
[4+2] cycloaddition reactions of various 1,3-diaza-1.3-Butadienes with ketenes
作者:Sujit N. Mazumdar、Mohinder P. Mahajan
DOI:10.1016/s0040-4020(01)86423-1
日期:1991.1
[4+2] cycloaddition reactions of 1-aryl-4-dimethylainino-1,3-diaza-1, 3-butadienes (), 1 -aryl-4-dimethylamino-2-methylthio-1, 3-diaza-1, 3-butadienes (), 1-aryl-4-methylthio-2-phenyl-4-sec. amino-1, 3-diaza-1, 3-butadienes () and 4, 4-bis(sec.amino)-1,2-diphenyl-1, 3-diaza-1, 3-butadienes () with monophenyiketene and similar cycloaddition reactions of , and with monochloroketene are described.