A facile synthesis of Pechmann dyes.
A facile synthesis of Pechmann dyes has been accomplished by the reaction of substituted N-phenacyl-4-dimethylaminopyridinium halides with dimethyl maleate in the presence of DBU. Based on a related 4-DMAP elimination product and an isolated monolactone intermediate a reaction mechanism has been proposed. The scope of this synthetic method is determined by the availability of α-haloaroyl or heteroaroyl derivatives. DBU=1,8-diazabicycloundec-7-ene, DMAP=4-dimethylaminopyridine.
Institute of Organic Chemistry, Technical University of Braunschweig, Hagenring 30, D-38106 Braunschweig (Germany).
Henning
H
Hopf
Peter G
PG
Jones
Alina
A
Nicolescu
Elena
E
Bicu
Lucian M
LM
Birsa
Dalila
D
Belei
Michael addition; Pechmann lactones; dimethylaminopyridine; dyes/pigments; ylids