Condensation of 2-hydroxyacetophenones with trichloroacetonitrile as a route to 2-trichloromethylchromones and 4-hydroxycoumarins
摘要:
Condensation of 2-hydroxyacetophenones with trichloroacetonitrile in the presence of N-methylanilinomagnesium bromide affords hydroxyaryl beta-amino-beta-trichloromethylvinyl ketones, which are converted into 2-trichloromethylchromones upon treatment with concentrated HCl. The resulting compounds react with alcoholic solutions of NH3 or KOH to Form 3-amino-1-(2-hydroxyaryl)-4,4,4-trichlorobut-2-en-1-ones and 4-hydroxycoumarins, respectively.
Reaction of Polyhaloalkyl-Substituted Chromones, Pyrones, and Furanones with Salicylaldehydes as a Direct Route to Fused 2<i>H</i>-Chromenes
作者:Vyacheslav Ya. Sosnovskikh、Vladislav Yu. Korotaev、Dmitry L. Chizhov、Igor B. Kutyashev、Danil S. Yachevskii、Olga N. Kazheva、Oleg A. Dyachenko、Valery N. Charushin
DOI:10.1021/jo060459x
日期:2006.6.1
Polyhaloalkyl-substituted chromones, γ-pyrones, and β-furanones react with salicylaldehydes in the presence of piperidine to give a wide variety of fused 2H-chromenes in good yields. This novel annulation reaction presumably proceeds by a tandem intermolecular oxa-Michael addition and subsequent intramolecular Mannich condensation.
Synthesis of 2-(2-hydroxyaroylmethylene)hexahydropyrimidines from 2-trichloromethylchromones and trimethylenediamine
作者:V. Ya. Sosnovskikh、V. A. Kutsenko
DOI:10.1007/bf02494859
日期:1999.11
The reactions of 2-trichloromethylchromones with trimethylenediamine in ethanol at room temperature afford 2-(2-hydroxyaroylmethylene)hexahydropyrimidines. Under analogous conditions, 2-methylchromone gives a mixture ofN,N′-trimethylenebis[3-amino-1-(2′-hydroxyphenyl)-2-buten-1-one] andN,N′-trimethylenebis(imine) of 2-hydroxyacetophenone.