Selective production of difluoromethyl methyl ether from chlorodifluoromethane using alkali metal carbonates

CHF2OCH3 (HFE-152a), an important starting material for synthesizing various C-2 hydrofluoroethers and a prospective alternative to CH3CF2Cl (HCFC-142b), has been found to be effectively produced from the reaction of CHF2Cl (HCFC-22) with alkali metal carbonates in methanol. Some alkali metal carbonates induce selective production of CHF2OCH3 with a small amount of CH(OCH3)(3), a major side product. Activities of alkali metal carbonates for producing CHF2OCH3 are in the order of K2CO3 > Na2CO3 > Li2CO3, suggesting that the solubility and ionization tendency of alkali metal carbonate in methanol play important roles in the reaction. (C) 2001 Elsevier Science B.V. All rights reserved.