4-Ethoxy-1,1,1-trifluoro-3-buten-2-one (ETFBO), a Versatile Precursor for Trifluoromethyl-Substituted Heteroarenes – a Short Synthesis of Celebrex® (Celecoxib)

Abstract

4-Ethoxy-1,1,1-trifluoro-3-buten-2-one (ETFBO) serves as a trifluoromethyl-containing building block for the preparation of trifluoromethyl-substituted thiophenes, furans, pyrrols, and piperazines. Key steps are an addition–elimination reaction to ETFBO followed by the thiazolium-catalyzed Stetter reaction. The scope of this chemistry was demonstrated in a new synthetic approach towards the COX-2 selective, nonsteroidal anti-inflammatory drug Celebrex® (celecoxib).