A process is disclosed for the conversion of fluorocarbons into fluorinated unsaturated compounds useful as monomers or other chemical precursors, such as C2H2F2. The process comprises reacting a hydrocarbon feed (20) arid a fluorocarbon feed (10) in a high temperature reactor (26), at sufficiently high temperature and sufficiently short resident time to form product mixture (28) having the fluorinated unsaturated compound as the major reaction product, and cooling (18) to a temperature sufficiently low to inhibit polymerisation of the unsaturated compound. The reaction product may then be processed by removal of higher molecular weight compounds (35) and acids (32) and optionally separated (44) into product components.