Difluoromethyl fluoromethyl carbonate

Among the carbonate solvents used in practical lithium batteries, linear carbonates such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and diethyl carbonate (DEC) are well-known good co-solvents (thinner) for EC and PC. The direct fluorination of DMC gave fluorinated derivatives such as mono-fluorinated one, fluo-romethyl methyl carbonate (FDMC), two di-fluorinated ones (bis(fluoromelhyl) carbonate, DFDMC, and difluormethyl methyl carbonate, gem-DFDMC), and tri-fluorinated ones (difluoromethyl fluoromethyl carbonate, TFDMC) as shown in Scheme 2.6 [33]. Three kinds of partially fluorinated DMCs except gm-DFDMC were obtained by fractional distillation of the fluorinated sample. 

The limitations of this reagent are several. It caimot be used to replace a single unactivated halogen atom with the exception of the chloromethyl ether (eq. 5) to form difluoromethyl fluoromethyl ether [461 -63-2]. It also caimot be used to replace a halogen attached to a carbon—carbon double bond. Fluorination of functional group compounds, eg, esters, sulfides, ketones, acids, and aldehydes, produces decomposition products caused by scission of the carbon chains. 

Bis(7-methylpurin-8-yl)methane underwent a high-yielding nitrosation and also reacted with dimethylformamide dimethylacetal under mild conditions at the exocyclic carbon, reflecting the high acidity of the hydrogens on the bridging carbon <1998JOC436> see Section 10.11.5.2.6. The introduction of 6-fluoromethyl and 6-difluoromethyl... 

The products from the partial fluorinations of butane32 and 2-methylpropane33 over cobalt(lll) fluoride are even more complex, 51 and 27 compounds, respectively, being identified. Most are C4F H10 n isomers which retained the original carbon skeletons, but up to 2% in each case has the carbon skeleton of the isomer (i.e., 2-methylpropane fluorination yields ca. 2% of products with the butane skeleton). From butane, at 140-230 C, only two compounds are present as more than 10% of the reaction product, 1 //,3//-octafluorobutane (11%) and 1 //,27f,4//-heptafluorobutane (14%). 2-Methylpropane is similar, at 140- 200°C only four compounds are present as over 10% of the product 2-(difluoromethyl)-l,1,1,2,3-pentafluoro-propane (14%), 2-(difluoromethyl)-l,l,2,3,3-pentafluoropropane (16%), 1,1,2,3,3-pentafluo-ro-2-(fluoromethyl)propane (24%), and l,l,2,3-tetrafluoro-2-(fluoromethyl)propane (15%). 

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