A rapid and versatile one-pot, 2 × 10 min microwave protocol for the preparation of N-1 and C-6 decorated 3,5-dichloro-2(1H)-pyrazinones was developed. Comparable reaction sequences using classical conditions require about 1–2 days of heating. The α-aminonitrile was first generated in a Strecker reaction and thereafter cyclized under microwave heating. The microwave approach developed offers the possibility of efficiently generating and utilizing functionalized 3-amino-5-chloro-2(1H)-pyrazinone-N-1-carboxylic acids as β-strand inducing core structures in a medicinal chemistry context. To illustrate the usefulness of the method, the synthesis of two novel 2(1H)-pyrazinone-containing Hepatitis C virus NS3 protease inhibitors is reported.
Base-catalysed direct introduction of carbon dioxide into acetylenic amines
作者:Mirco Costa、Gian Paolo Chiusoli、Marco Rizzardi
DOI:10.1039/cc9960001699
日期:——
N-Alkylprop-2-ynylamines readily react with carbon dioxide in the presence of catalytic amounts of strong organic bases and undergo intramolecular cyclization to 5-methylene-1.3-oxazolidin-2-ones in good yields.
Superbase catalysis of oxazolidin-2-one ring formation from carbon dioxide and prop-2-yn-1-amines under homogeneous or heterogenous conditions
作者:Mirco Costa、Gian Paolo Chiusoli、Davide Taffurelli、Giulio Dalmonego
DOI:10.1039/a800453f
日期:——
N-alkyl-substituted prop-2-yn-1-amines and N-tri-, tetra- and penta-alkyl-substituted guanidines or other strong organic bases assemble under the action of carbon dioxide to afford carbamates, from which methyleneoxazolidinones 2 are formed by ring closure. If alkyl or cycloalkyl chains of appropriate length are present in the guanidines the reaction readily occurs under heterogenous conditions without
Copper catalyzed aminolysis of bromoallenes as a new efficient route to propargylamines
作者:Anna Maria Caporusso、Roberto Geri、Carmela Polizzi、Luciano Lardicci
DOI:10.1016/0040-4039(91)80138-v
日期:1991.12
An efficient procedure of general applicability for the synthesis of secondary and tertiary propargylamines by copper mediated aminolysis of 1-bromo-1,2-dienes is described.