GB283163A - - Google Patents

Abstract

283,163. I. G. Farbenindustrie Akt.- Ges. Jan. 5, 1927, [Convention date]. Ethylamines; heterocyclic bases; hydrocarbons. -Organic bases are obtained by passing a mixture of acetylene and ammonia over a catalyst consisting of an inorganic salt which is capable of forming an addition compound with ammonia and is not reduced by acetylene, such as a metal chloride. The formation of acetonitrile is negligible. Preferably, the catalyst is a halide which forms an additional compound with ammonia which is stable at the reaction temperature. Suitable catalysts may be prepared by soaking a carrier such as pumice, asbestos, or coke, dried at 500-600‹ C., in a solution of an anhydrous halide in absolute alcohol or methanol, evaporating the solvent, and, if desired, treating the mass with ammonia at ordinary or raised temperature. The catalysts mentioned are obtained from zinc chloride, an equi-molecular mixture of zinc and ferric chlorides, and an equi-molecular mixture of cadmium and cupric chlorides. The reaction is effected at 280-350‹ C., but as the reaction is exothermic it is preferred to use a diluent gas which is constantly returned to the catalytic apparatus. In an example, 400 litres of ammonia per hour are circulated over a zinc chloride catalyst and 10 litres of ammonia and 10-20 litres of acetylene are added to the stream while 10 litres are withdrawn after passing the catalytic apparatus. The gas withdrawn is cooled to separate liquid products, and the uncondensed gas contains, besides ammonia, some hydrogen and heavy hydrocarbons. The liquid products comprise 15-20 per cent, chiefly diethylamine, 5-6 per cent tri-ethylamine and cyclic bases rich in hydrogen, 60-65 per cent a- and gamma-methyl-pyridine, and 10-12 per cent higher methyl pyridines and polynuclear bases. i The Specification as open to inspection under Sect. 91 (3) (a) describes the catalysts as preferably capable of forming addition compounds with pyridine, and does not limit them to those which are not reduced by acetylene. This subject-matter does not appear in the Specification as accepted.