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Practical and Green Protocol for the Synthesis of Substituted 4 H ‐Chromenes Using Room Temperature Ionic Liquid Choline Chloride–Urea
Author(s) -
Revanna C. N.,
Swaroop T. R.,
Raghavendra G. M.,
Bhadregowda D. G.,
Mantelingu K.,
Rangappa K. S.
Publication year - 2012
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.880
Subject(s) - chemistry , ionic liquid , aldehyde , choline chloride , knoevenagel condensation , urea , cyclohexane , methylene , chloride , solvent , condensation , organic chemistry , inorganic chemistry , catalysis , physics , thermodynamics
An efficient and convenient synthesis of substituted 4 H ‐chromenes is described using room temperature ionic liquid (RTIL) choline chloride–urea in one pot under solvent free conditions. Three‐component Knoevenagel condensation of an aromatic aldehyde, with an active methylene compound, and a cyclohexane dione is reported. This new approach has advantage of excellent yields (82–96%), clean reaction, and short reaction time (15–30 min) at room temperature.