Zeneca Limited

Keith Moorhouse

Stephen Martin Brown

Martin Charles Bowden

Thomas Gray

Alan Raymond Jackson

Sean James Doyle

There is provided a process for the preparation of 1,1,1-trichlorotrifluororethane in which 1,1-dichloro-2,2,2-trifluoroethane is subjected to chlorination by bringing the 1,1-dichloro-2,2,2-trifluoroethane into contact with chlorine within a reaction vessel characterised in that the process is conducted in the liquid phasein the presence of a chemical free radical initiator under a pressure of from 1 to 20 bar and at a temperature within the range 50 to 120&deg; C., and the product is separated from the reaction mixture by fractional distillation. The product is useful in the manufacture of insecticides.

Chlorination process

A process for preparing a compound of formula (I), ##STR1## where R.sup.1 is optionally substituted alkyl or phenyl, R.sup.2 is COOH, and R.sup.3 and R.sup.4 are independently selected from hydrogen, halo, haloalkyl, nitro, hydroxy, alkoxy, haloalkoxy or alkoxyalkoxy; which process comprises oxidising a compound of formula (II) ##STR2## where R.sup.1, R.sup.3 and R.sup.4 are as defined in relation to formula (I) and R.sup.5 is H, halo or C.sub.1-4 alkyl with sodium hypochlorite or sodium chlorite in the presence of a catalytic amount of a ruthenium or palladium compound and a phase transfer catalyst in an organic solvent at a pH of 7-11.

Growing community of inventors

Huddersfield, United Kingdom

Keith Moorhouse