2-(Arylamino)-4-oxo-4H-chromene-3-carbaldehyde 3 (R2 = aryl) produces 12H-chromeno[2,3-b]quinolin-12-one 4 when treated with sarcosine, piperidine or diethylamine, but produces 3,3′-methylenebis(2-arylamino-4H-chromen-4-one) 8 when treated with the same amine in the presence of an excess of formaldehyde. Compound 3 (R2 = alkyl) was found to be less reactive than the N-aryl analogues towards the deformylative
Rearrangements of N-alkyl-/aryl-nitrones derived from 4-oxo-4H-1-benzopyran-3-carboxaldehyde––a solvent-dependent process
作者:Tarun Ghosh、Chandrakanta Bandyopadhyay
DOI:10.1016/j.tetlet.2004.06.033
日期:2004.8
C-(4-Oxo-4H-1-benzopyran-3-yl)-N-alkyl-/aryl-nitrones derived from 4-oxo-4H-1-benzopyran-3-carboxaldehyde, rearrange to 2-alkyl-/aryl-amino-3-formylchromone and/or 3-(alkyl-/aryl-aminomethylene)chroman-2,4-dione depending upon the reaction medium. 3-(Alkylaminomethylene)chroman-2,4-dione has been utilized in the synthesis of 1-benzopyrano[3,4-d]isoxazole-4-one. (C) 2004 Elsevier Ltd. All rights reserved.
Maiti, Sourav; Panja, Suman Kalyan; Bandyopadhyay, Chandrakanta, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 2009, vol. 48, # 10, p. 1447 - 1452