Ethyl difluoroacetate

Difluoroacetic acid undergoes reactions typical of a carboxylic acid such as forming an ester when heated with an alcohol and sulfuric acid. Typical esters are methyl difluoroacetate [433-53-4], bp, 85.2°C, and ethyl difluoroacetate [454-31-9], bp, 99.2°C. It can also be photochemicaHy chlorinated to chlorodifluoroacetic acid [76-04-0] or brominated in the presence of iron to bromodifluoroacetic acid [667-27-6] (37,38). 

Yamaki et al. [14-16] investigated the thermal stability of fluorinated esters, which are the same fluorinated esters used as additives to improve the cycling performance reported by Nakajima et al. [12,13] prior to our study. In this study, partially fluorinated carboxylic acid esters (Table 20.1) were used as the electrolyte solvent and LiPFe as the salt. LiPFe was dissolved in methyl difluoroacetate (MEA) and ethyl difluoroacetate (EFA) to a salt concentration of 1 M. In the other fluorinated esters, however, LiPFe salt could be dissolved to a salt concentration of less than 0.2 M. Therefore, the solutions of fluorinated esters (P and 2 ) with 0.2 M of LiPFe were used, and the other fluorinated esters were saturated with LiPFe. For comparison, the solutions of corresponding esters with 0.2 M LiPFe were prepared. Similar measurements were performed employing the conventional electrolyte solution used in lithium batteries 1 M LiPFe/EC + DMC (1 1 by vol). 

The cycloaddition of the 2,4-dialkoxy-l,l-difluoro-bata-l,3-diene 11 to benzyloxyacetaldehyde has afforded the unsaturated pyranoside 12 from which die racemic 2,4-dideoxy-4,4-difluotopyranosides 13 were obtained. The synthesis of 2-deoxy-2,2-difluoro-D-ribono-l,4-lactDne has been achieved by application of the Refomiatsl reaction of an ethyl difluoroacetate derivative with 2,3-0-cyclohexylidene-D-glyceraldehyde. A study of the formation of 6-deoxy-6-fluoTohexonolactones from 5,6-anhydro-hexonolactones and of 2-deoxy-2-fluoropentone-l,4-l tones from 2,3-anhydro-pentono-l,4-lactones has been reported, and the synthesis of some 3-amino-2,3-dideoxy-2-fluoro-D-xylose derivatives has been reported. ... 

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