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A Facile Synthesis of Pechmann Dyes |
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| Authors: | Prof Henning Hopf Prof Peter G Jones Dr Alina Nicolescu Prof Elena Bicu Dr Lucian M Birsa Dr Dalila Belei |
| Institution: | 1. Institute of Organic Chemistry, Technical University of Braunschweig, Hagenring 30, D‐38106 Braunschweig (Germany);2. Institute of Inorganic and Analytical Chemistry, Technical University of Braunschweig, Hagenring 30, D‐38106 Braunschweig (Germany);3. “Petru Poni” Institute of Macromolecular Chemistry, Aleea Grigore Ghica 41A, 6600, Iasi (Romania);4. Department of Chemistry, ‘Al. I. Cuza' University of Iasi, 11 Carol I, 700506 Iasi (Romania) |
| Abstract: | 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. |
| Keywords: | dimethylaminopyridine dyes/pigments Michael addition Pechmann lactones ylids |