PROCESS FOR PREPARING BIS-(TRIFLUOROMETHYL) -PHENYL -ACETIC ACIDS AND ALKYL ESTERS THEREOF AND DIALKYL BIS- (TRIFLUOROMETHYL) - PHENYL -MALONATES

摘要

Preparation of (bis-(trifluoromethyl)-phenyl)-acetic acids (I) involves (a) reacting a bromo- or iodo-bis-(trifluoromethyl)-benzene (II) with a di-(1-4C alkyl) malonate (III) in presence of a deprotonating reagent and a copper salt, then (b) saponifying and decarboxylating the product in a basic medium. Also new are a method for preparing dialkyl phenylmalonates (IV) and alkyl phenylacetates (V) using step (a); and the compounds (IV). Independent claims are included for: (i) the preparation of (bis-(trifluoromethyl)-phenyl)-acetic acid esters, by step (a) as above followed by cooling the reaction mixture, acidifying to pH 5-9, separating the solids, washing the residue with an ether or alcohol and recovering product from the combined filtrate and washings by distillation under reduced pressure; (ii) the preparation of a mixture of dialkyl phenylmalonates of formula (IV) and alkyl phenylacetates of formula (V), by step (a) as above followed (before saponification and complete decarboxylation) by treating the reaction mixture with water and acid, heating and working up the mixture by extraction and distillation; (iii) the preparation of (IV) by working up the mixture obtained in (ii) by column chromatography, fractional distillation or thin film distillation; (iv) the preparation of (V) by working up the mixture obtained in (ii) by distillation under reduced pressure; and (v) (IV) as new compounds. R = 1-4C alkyl.