1-Ethoxy-3-trifluoromethyl-1,3-butadiene and its 2-bromo- and 2-phenyl-substituted derivs. have been prepd. by Wittig methylenation of the corresponding 4-ethoxy-1,1,1-trifluoro-3-buten-2-ones, which in turn are readily accessible from trifluoroacetic acid. The electron-rich/electron-poor dienes combine smoothly with di-Me acetylenedicarboxylate and Me propiolate to provide trifluoromethyl-substituted phthalates or benzoates. Satisfactory yields of 4-(trifluoromethyl)pyridinecarboxylic acids can even be achieved with Me cyanoformate, a less reactive dienophile, if a large excess of the dienophile is employed. [on SciFinder (R)]
Title
1-Ethoxy-3-trifluoromethyl-1,3-butadiene and congeners as Diels-Alder components opening an entry to functionalized (trifluoromethyl)benzenes and -pyridines
Published in
European Journal of Organic Chemistry
Issue
9
Pages
1490-1492
Date
2002
Note
CAN 137:216728 25-18 Benzene, Its Derivatives, and Condensed Benzenoid Compounds Departement de Chimie,Ecole Polytechnique Federale,Lausanne,Switz. Journal 1434-193X written in English. 350-92-5 (1,1,1-Trifluoro-3-phenyl-2-propanone); 762-42-5 (Dimethyl acetylenedicarboxylate); 922-67-8 (Methyl propiolate); 1779-49-3 (Methyltriphenylphosphonium bromide); 17640-15-2 (Methyl cyanoformate); 59938-06-6; 341527-27-3; 455941-88-5 Role: RCT (Reactant), RACT (Reactant or reagent) (1-ethoxy-3-(trifluoromethyl)-1,3-butadiene and congeners as Diels-Alder components opening an entry to functionalized (trifluoromethyl)benzenes and -pyridines); 455941-77-2P; 455941-79-4P; 455941-83-0P Role: RCT (Reactant), SPN (Synthetic preparation), PREP (Preparation), RACT (Reactant or reagent) (1-ethoxy-3-(trifluoromethyl)-1,3-butadiene and congeners as Diels-Alder components opening an entry to functionalized (trifluoromethyl)benzenes and -pyridines); 728-47-2P; 2967-66-0P; 107317-58-8P; 455941-78-3P; 455941-80-7P; 455941-82-9P; 455941-84-1P; 455941-85-2P; 455941-86-3P Role: SPN (Synthetic preparation), PREP (Preparation) (1-ethoxy-3-(trifluoromethyl)-1,3-butadiene and congeners as Diels-Alder components opening an entry to functionalized (trifluoromethyl)benzenes and -pyridines)
Record creation date
2006-03-03