Production of substituted thiophenes

Thiophene derivatives are produced when sulphur is reacted with an olefinic compound of the formula RCH=CH2, where R is a hydrocarbon radical or a hydrocarbon radical carrying substituents which are inert under the conditions of the reaction, the reaction being carried out in the presence of a compound which is known for use commercially as a vulcanization accelerator. Compounds mentioned for this purpose include mercaptobenzothiazole, hexamine, aldehyde amine condensation products, diphenyl guanidine, thioureas, thiophenols, dithiocarbamates, trithiocarbamates, xanthates and thiuram disulphides. The reaction is carried out by raising the temperature of the mixture of catalyst, sulphur and olefine together with a diluent if the latter is used, to a point where vigorous evolution of hydrogen sulphide occurs. Starting materials include aliphatic olefines containing up to 20 carbon atoms of which propylene, butene-1 and butene-2, the lower polymers or copolymers derived by cracking long-chain hydrocarbons such as paraffin wax. Aromatic olefins include styrene and its substitution products such as alkyl styrenes. An example is given using styrene as the olefine and mercaptobenzothiazole as the catalyst.