Patent GB-977755-A (GB)
Title: Method of preparing aromatic nitriles
IPC: B01J23/888
Filed: 1963-08-30
Abstract: Catalysts used in the production of aromatic nitriles (see Division C2) are prepared by (1) calcination of tungstic acid or its salt, e.g. ammonium paratungstate; or (2) calcination of a mixture of tungstic acid or its salts and the salts of at least one of the metals selected from the group consisting of magnesium, aluminium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, silver, cadmium, tin, tellurium, barium, lead, bismuth, thorium and uranium.  The catalyst obtained by the method (1) is presumed to be made up partly or wholly of oxides of tungsten or the hydrates thereof, and that obtained by the method (2) is thought to be (a) a mixture of the oxides of tungsten and the metals or the hydrates thereof, (b) tungstate of the metals, or (c) a mixture of both (a) and (b). In examples, (1) ammonium paratungstate is treated with nitric acid and the tungstic acid produced separated pelleted and calcined for 4 hours at 540 DEG  C.; (2) instead of treatment with nitric acid the ammonium paratungstate is treated with aluminium nitrate, manganese nitrate, lead nitrate, zinc nitrate, silver nitrate, cadmium nitrate, chromium nitrate, cobalt nitrate, nickel nitrate and copper nitrate to produce the corresponding metal paratungstate which is filtered pelleted and calcined for four hours at 540 DEG  C.; (3) tungstic acid as obtained in Example 1 is mixed with titanic acid formed from titanium chloride and ammonia, pelleted and calcined for 4 hours at 540 DEG  C.; (4) tungstic acid obtained as in Example 1 is mixed with magnesium nitrate and the mixture pelleted and calcined for 4 hours at 540 DEG  C.  The tungstic acid may also be mixed with ferric nitrate, molybdic acid, bismuth nitrate or thorium nitrate the mixture in each case being pelleted and calcined for 4 hours at 540 DEG  C.; (5) To a precipitate of manganese paratungstate obtained from ammonium paratungstate and manganese nitrate there is added ammonium paratungstate and the mixture dried and calcined for 4 hours at 540 DEG  C.; (6) to a solution of ammonium paratungstate ammonium chlorostannate is added and the stannic tungstate formed is filtered, pelleted and calcined for 4 hours at 540 DEG  C.; (7) manganese paratungstate obtained from ammonium paratungstate and manganese nitrate is mixed with metallic tellurium dissolved in nitric acid and the mixture pelleted and calcined for 4 hours at 540 DEG  C.; (8) barium paratungstate precipitated from ammonium paratungstate and barium chloride is filtered and pelleted and calcined for 4 hours at 540 DEG  C.; (9) to a solution of ammonium paratungstate uranyl acetate is added and the solution sprayed on to alumdum heated 250 DEG  C. after which it was calcined for 4 hours at 540 DEG  C.ALSO:Aromatic nitriles are prepared by reacting an alkyl-substituted aromatic compound e.g. o-m-p-xylene, toluene, a methyl-substituted pyridine, alpha-picoline or 2,5-lutidine with ammonia and molecular oxygen in the vapour phase at a temperature in the range of 350-600 DEG C. using a catalyst comprising oxygen-containing compounds of tungsten preferably also including as promotors oxygen-containing compounds of at least one of the metals magnesium, aluminium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, silver, cadmium, tin, tellurium, barium, lead, bismuth, thorium and uranium. In an example o-xylene, ammonia and air are passed at 450 degrees over a catalyst obtained by heating ammonium paratungstate suspended in water, adding nitric acid, separating and pelleting and calcining the tungstic acid obtained to produce phthalonitrile. In another example gaseous alphapicoline is reacted with ammonia and air in the presence of a catalyst to produce a -cyanopyridine.  Several other examples are given.