GB829920A - Production of thioamides and nitriles - Google Patents

Abstract

Aliphatic hydrocarbons, non-aliphatic hydrocarbons having at least one alkyl group, or partially oxidized derivatives of these, are converted to thioamides or nitriles by reacting them with elemental sulphur and anhydrous ammonia in a pressurized reaction zone at a temperature above 400 DEG F., there being no contact between the sulphur and the hydrocarbon or its derivative until the latter are at a temperature above 400 DEG F. To produce thioamides the reaction product is cooled without releasing gases from the reaction zone; to produce nitriles, gases are bled from the reaction zone, while maintaining the reaction temperature, until the pressure is approximately atmospheric. The term "partially oxidized hydrocarbon" is defined as meaning a hydrocarbon derivative which contains at least one carbon atom at a higher oxidation state than in the original hydrocarbon, and at least one carbon atom the oxidation state of which can be raised. The organic reactant and the ammonia (which may be used in excess) may be heated to the reaction temperature separately or together; desirably the sulphur is also pre-heated to the reaction temperature. Instead of sulphur there may be used materials which yield sulphur under the reaction conditions, such as anhydrous ammonium polysulphide, mixtures of H2S and SO2, and mixtures of ammonium sulphite and H2S. Inert diluents, such as benzene and diphenyl, may be employed. Pressures above 200 p.s.i.g. are preferred. Specified reactions are the conversion of m-xylene to 1-3-di-thiocarbamyl-benzene and to isophthalonitrile, cumene to b -phenyl-thiopropionic acid amide, amyl alcohol to thiopentanoic acid amide, and toluic acid to ammonium p-thiocarbamylbenzoate and to ammonium p-cyano-benzoate.