VERFAHREN ZUR HERSTELLUNG VON CARBONYLFLUORID

Process for the preparation of aliphatic fluoroformates by reaction of carbonyl fluoride with an aliphatic alcohol in the presence of sodium fluoride in an ether solvent at -20 to +50 degrees C is new. The sodium fluoride is preferably a powder with a specific surface area of 0.1 m2/ g or more and a particle size below 20 mum. Preferably 1.1 to 2 moles of carbonyl fluoride are used per mole of alcohol, suitable solvents being tert. butyl methyl ether, dioxan, tetrahydrofuran, 2-methyl tetrahydrofuran, dibenzyl ether, and ethylene glycol or polyethylene glycol dimethyl ethers. The carbonyl fluoride is prepared by reaction of phosgene, diphosgene, or triphosgene or their mixtures with excess powdered sodium fluoride in a polar aprotic solvent such as acetonitrile, at 25 - 120 degrees C, followed by condensation of the resultant gas at 0 to -50 degrees C.