Simple method for the preparation of dialkyl (2,3-dihydro-1,3-thiazol-2-YL) -phosphonates

摘要

A simple synthesis of dialkyl (2,3-dihydro-1,3-thiazol-2-yl)-phosphonates from thiazolium salts and trialkyl phosphites is described. The series of dialkyl (2,3-dihydro-1,3-thiazol-2-yl)-phosphonates with various substituents in positions 3, 4, and 5 of the thiazole ring were prepared. However, only phosphonates with an aryl on the nitrogen atom were stable enough for chromatographic purification, although all the new phosphonates are very sensitive to oxidation. We made efforts to apply dialkyl (2,3-dihydro-1,3- thiazol-2-yl)-phosphonates in a Horner-Wadsworth-Emmons reaction, but the generated antiaromatic anion of phosphonate decomposed quickly, even at -70°C.