Unique zeolite-catalyzed synthesis of nitroketene S,N-acetals
作者:T.Indrasena Reddy、Baburao M. Bhawal、Srinivasachari Rajappa
DOI:10.1016/s0040-4020(01)86309-2
日期:1993.3
7a–c) derived from various primary amines and amino acid esters [glycine, (L)-alanine and (L)-phenylalanine] have been condensed with nitromethane in the presence of the rare-earth exchanged zeolite RE(70%)Na Y to give the S,N-acetals (5a–g, 8a–c). Mercuric chloride catalyzed hydrolysis of these (8a–c) has led to the nitroacetyl derivatives (9a–c). The glycine derivative (7a) gives a dimeric product
Catalytic and computer simulation studies of carbon-sulphur bond cleavage over zeolite-Y
作者:B. M. Bhawal、R. Vetrivel、T. Indrasena Reddy、A. R. A. S. Deshmukh、S. Rajappa
DOI:10.1002/poc.610070708
日期:1994.7
undergo carbon–carbon bond formation followed by carbon–sulphurbondcleavage in the presence of zeolite catalysts to give 1-substituted amino-1-methylthio-2-nitroethenes. This carbon-sulphurbondcleavage is facilitated by the presence of rare earth cations in the zeolite-Y framework. The shape selectivity of the zeolite also plays an important role in this cleavagereaction. Force field calculations
Reaction of Dimethyl<i>N</i>-Aryl- and<i>N</i>-Alkylcarbonimidodithioates with Aminoacetaldehyde Diethyl Acetal: A Direct Synthesis of 1-Aryl- and 1-Alkyl-2-methylthioimidazoles
The reaction of dimethyl N-aryl- or N-alkylcarbonimidodithioates with aminoacetaldehyde diethyl acetal in refluxing acetic acid affords 1-aryl or 1-alkyl-2-methylthioimidazoles in good yields. Dimethyl N-isopropylcarbonimidodithioate gave 1-isopropylimidazole-2(3H)-thione under similar conditions.
Synthesis of 4-Unsubstituted β-Lactams<i>via</i>Dithiocarbonimidates
作者:S. D. Sharma、Usha Mehra、J. P. S. Khurana、S. B. Pandhi
DOI:10.1055/s-1987-28144
日期:——
Cycloaddition of dithiocarbonimidate 1 to the ketene generated in situ from phenoxyacetylchloride in the presence of triethylamine affords the 4-dithioalkyl-2-azetidinones 2 in good yields. Facile conversion of 2 to the 4-unsubstituted ß-lactams 3 can be accomplished by desulfurization with Raney-Nickel. Formation of several interesting products during attempts to bring a carbonyl function at C-4 in 2 has also been described.