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A High Yield Procedure for the Preparation of 2‐Hydroxynitrostyrenes: Synthesis of Imines and Tetracyclic 1,3‐Benzoxazines
Author(s) -
Tena Pérez Víctor,
Fuentes de Arriba Ángel L.,
Monleón Laura M.,
Simón Luis,
Rubio Omayra H.,
Sanz Francisca,
Morán Joaquín R.
Publication year - 2014
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.201402016
Subject(s) - chemistry , phosgene , imine , salicylaldehyde , knoevenagel condensation , yield (engineering) , ammonium acetate , organic chemistry , combinatorial chemistry , polymer chemistry , catalysis , schiff base , materials science , high performance liquid chromatography , metallurgy
Attempts to synthesize 2‐hydroxynitrostyrenes by a Knoevenagel condensation of salicylaldehyde and subsequent elimination were unsuccessful because of the formation of a stable imine. This could be easily prevented by using secondary amines to catalyze the reaction, which then afforded 2‐hydroxynitrostyrenes in high yields. In addition, the stable imine that was formed by employing ammonium acetate underwent a reaction with phosgene to allow the preparation of benzoxazines in good yields.