Abstract: Raney nickel catalysts obtainable by a process in which the melt of an alloy comprising 50 to 94 wt. % aluminum, 10 to 50 wt. % nickel, 0 to 20 wt. % iron, 0 to 15 wt. % cerium, cerium mixed metal, vanadium, niobium, tantalum, chromium, molybdenum or manganese and, optionally, further glass-forming elements is allowed to solidify rapidly with a cooling rate of >104 K/s and the rapidly solidified alloy is then subjected to a treatment with organic or inorganic bases are described. A process for the preparation of the Raney nickel catalysts mentioned and their use in the hydrogenation of organic compounds, in particular aromatic nitro compounds, are furthermore described.

Abstract: Organic isocyanates are continuously prepared by reacting primary organic amines with phosgene in the presence of an inert, organic solvent, with the reaction mixture being circulated by means of a bubble column at a temperature of from 60.degree. to 100.degree. C. and with the ratio of the quantity of the circulated amine reaction products to the quantity of the amine supplied of from 100:1 to 5:1.

Abstract: A continuous process for the preparation of aromatic diisocyanates by phosgenation of the corresponding diamines, in which the reaction is carried out in the gas phase. The mean contact time for the gaseous reactants is from 0.5 to 5 seconds with a mean deviation of no more than 6%. The product diisocyanate is obtained in yields of over 95%.

Abstract: The present invention relates to a process for the preparation of diisocyanates corresponding to the formulaOCN--R--NCOwhereinR denotes a (cyclo)aliphatic hydrocarbon group with up to 15 carbon atomsby phosgenation of the corresponding diamines represented by the formulaH.sub.2 N--R--NH.sub.2in the gas phase, characterized in that(a) the diamines in vapor form, optionally diluted with an inert gas or with the vapors of an inert solvent, and phosgene are separately heated to temperatures of about 200.degree. to 600.degree. C. and continuously reacted together in a cylindrical reaction chamber which is free from moving parts and heated to about 200.degree. to 600.degree. C., while a turbulent flow is maintained in the reaction chamber.

Abstract: Aromatic diamino compounds are produced by hydrogenating the corresponding dinitro compounds in the presence of a modified Raney catalyst. The modified Raney catalyst is obtained by treating an alloy made up of 50-95 wt % of aluminum, 4-45 wt % nickel and/or cobalt and 1-46 wt % of at least one modifying metal with an alkali material. The modifying metal is selected from the metals of the first, fourth, fifth, sixth, seventh and eighth subgroups of the Periodic Table of Elements. The hydrogenation is preferably carried out at from 170.degree. to 250.degree. C. and a pressure of 15-50 bar. The heat generated during hydrogenation is preferably used to produce steam.