A. Alizadeh, A. Rezvanian, Longguan Zhu
Dec 1, 2007
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0
Influential Citations
12
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Journal
Helvetica Chimica Acta
Abstract
An effective route to novel 4-(alkylamino)-1-(arylsulfonyl)-3-benzoyl-1,5-dihydro-5-hydroxy-5-phenyl-2H-pyrrol-2-ones 10 is described (Scheme 2). This involves the reaction of an enamine, derived from the addition of a primary amine 5 to 1,4-diphenylbut-2-yne-1,4-dione, with an arenesulfonyl isocyanate 7. Some of these pyrrolones 10 exhibit a dynamic NMR behavior in solution because of restricted rotation around the CN bond resulting from conjugation of the side-chain N-atom with the adjacent α,β-unsaturated ketone group, and two rotamers are in equilibrium with each other in solution (10 ⇌ 11; Scheme 3). The structures of the highly functionalized compounds 10 were corroborated spectroscopically (IR, 1H- and 13C-NMR, and EI-MS), by elemental analyses, and, in the case of 10a, by X-ray crystallography. A plausible mechanism for the reaction is proposed (Scheme 4).