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Preparation of 2‐Amino‐4 H ‐chromene Derivatives from Coumarins in Basic Media
Author(s) -
Curini Massimo,
Rosati Ornelio,
Marcotullio Maria Carla,
Montanari Francesca,
Campagna Valerio,
Pace Vittorio,
Cravotto Giancarlo
Publication year - 2006
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200500495
Subject(s) - chemistry , coumarin , piperidine , derivative (finance) , ethyl cyanoacetate , yield (engineering) , michael reaction , nucleophile , nucleophilic addition , base (topology) , organic chemistry , combinatorial chemistry , malononitrile , catalysis , mathematical analysis , materials science , mathematics , financial economics , economics , metallurgy
The reaction of coumarin with cyanoacetate derivatives in the presence of a nucleophilic base (alkoxides or piperidine) follows an interesting pathway that involves both a coumarin skeletal rearrangement and a Michael addition, via a coumaric acid derivative, to afford a substituted 4 H ‐chromene skeleton. The particular behavior of this process influences the performance and the type of compounds that can be obtained. We demonstrate that the use of an excess of cyanoacetate affords the 4 H ‐chromene derivative in high yield. An explanation of the mechanism involved in this process is proposed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)