PURPOSE: To obtain the subject compound useful as intermediates for various catalysts, agrochemicals, pharmaceuticals, lubricating oils, etc., on an industrial scale in high yield at a low cost by oxidizing dichloropentafluoropropane with oxygen under heating in the presence of a small amount of water.
CONSTITUTION: An autoclave is charged with a dichloropentafluoropropane (e.g. 3,3-dichloro-1,1,1,2,2-pentafluoropropane) and a small amount of water and heated to 260°C. Oxygen is introduced into the autoclave to 40kg/cm2 pressure and maintained for 30 min to effect the thermal oxidation reaction. After the reaction, the content of the autoclave is collected in a trap cooled with liquid nitrogen. The trap is dipped in a dry ice-ethanol bath to remove the unreacted oxygen and the produced hydrochloric acid and obtain the objective polyfluoropropionic acid and its acid halide useful as intermediates for various catalysts, agrochemicals, pharmaceuticals, lubricating oils, etc., in high yield. The selectivities of pentafluoropropionic acid and pentafluoropropionic acid chloride attained by the process are 10% and 85%, respectively.
ONISHI KEIICHI
OKAMOTO SHUICHI
TANUMA TOSHIHIRO
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