a n l I / E C l U r z i t Processes Review
Amination by Reduction by Jesse Werner, General Aniline & Film Corp., New York, N.Y.
b
Interest in catalytic methods for reduction remained at the high level of past years
b b
Russian studies on the B6champ method were concerned with continuous operation Significant work appeared on the use of lithium aluminum hydride as a reducing agent
DURING
the 12-montli Deriod since the appearance of the last revieiv in this series on amination by reduction (I EC, September 1959, Pt. 11), most of the work reported in the technical and patent literature has been on the subject of catalytic reduction, as in past years. Relatively little has been published on the BCchamp (iron and acid) method, on sulfide reductions, or on electrolytic reductions. Some significant work has appeared on the use of lithium aluminum hydride as a powerful reducing agent. I n the area of catalytic hydrogenation, investigations were carried out on catalysts and conditions for continuous reduction of nitro compounds and for the reduction of nitriles to amines. \Vork was also reported on the catalytic reduction of complex nitro compounds and on the use of hydrazine hydrate and Raney nickel. T h e only significant studies on the Btchamp method were Russian references on continuous operations. O n e important contribution was made in the area of sulfide reductions: and several investigations on the electrolytic method were reported. Several important pieces of work involving the use of lithium aluminum hydride were published. T h e types of organic compounds in these studies included aromatic, aliphatic, and heterocyclic compounds. The groups reduced were nitro, azo, cyano. and heterocyclic moieties. I
Catalytic Reduction Among the newer methods used for the production of aniline in the Lynited
States is the American Cyanamid Co.’s fluid bed catalytic reduction process. This method is used a t Cyanamid’s IVillow Island, I V . V a . , plant, which has a rated annual capacity of 24 million pounds. T h e copper on silica catalyst used in this process was patented last year ( 70). Another patent was granted to Winstroin (23) on an improved catalyst for vapor phase hydrogenation of nitro compounds. It consists of nickel sulfide associated with amorphous alumina. Kagan and others ( 9 ) have been granted a Russian patent on the vapor phase hydrogenation of nitrobenzene to aniline over a catalyst comprised of nickel, vanadium pentoxide, and alumina. Sobolev and BerezovskiY (76) have described the production of 3,4-xylidine by hydrogenating 2-chloromethyl-4-nitrotoluene over Raney nickel in an alcohol in the presence of alkaline agents a t 100° to 120’ c. dnd 35 a t m . or higher, A patent has been issued to Hamilton and Spiegler ( 8 ) on the preparation of special palladium catalysts for the reduction of aromatic nitro compounds to amines. Suzuki (78) has described the reduction of various derivatives and analogs of p-nitrosalicylic acid to the corresponding amines by the use of hydrogen over Raney nickel. Two British patents have been issued on the catalytic hydrogenation of x) lylenediamines. phthalonitriles to T h e first ( 3 ) covers the reduction of m- and p-phthalonitrile in the liquid phase in the presence of ammonia over a nickel or cobalt catalyst a t high pressures. T h e second (1)describes a sim-
ilar reduction of crude phthalonitriles, prepared from the corresponding phthalic acids and not isolated, using ammonia and a cobalt catalyst a t high pressures. Another British patent ( 7 ) concerns the hydrogenation of fatty nitriles to amines in the presence of ammonia over a composition catalyst. Freidlin and others ( 6 ) have studied the catalytic hydrogenation of adiponitrile over a skeleton nickel catalyst deactivated with copper or titanium. They have been able to vary the ratios of the resulting mixture of hexamethylenimine, hexamethylenediamine, and f-aminocapronitrile and have been able to obtain a preponderance of the latter. Vanyushina and others (22) have discussed analytical control of the catalytic hydrogenation of adiponitrile to hexamethylenediamine and suggest infrared spectroscopy as the method of choice. T h e same reduction over a cobalt boride catalydt, in yields of up to 947,, was described by Polkovnikov and others ( 73). .4 patent was granted to Scalera and others (75) concerning the hydrogenation of nitronaphthotriazole quinones to the corresponding amines over a palladiumon-charcoal catalyst. Another patent was issued to Fidler (5) on the catalytic hydrogenation of nitrobenzene over platinum oxide or palladium metal in the presence of anhydrous hydrofluoric acid to yield p-fluoroaniline in good yield. Terent’ev and others (79) have described the catalytic reduction of several nitriles with hydrazine hydrate, in the presence of Ranev nickel, to yield only primary amines. VOL. 53. NO. 1
JANUARY 1961
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q Unit Processes Review metal salts speed u p the reaction markedly and improve the yield considerably. The reaction of lithium aluminum h>.dride on methyl esters of a-nirrocc-meth>-l Fatty acids was investigated by Reinheckel and Tauber ( 7 4 ) . ‘They found no formation of the corresponding amines, as might be expected. Instead, they obtained 2-aminoalkanes and o r 2-h~rdroxyla~nino-2-methyl-1 -alkanols.
literature Cited (1) Armour & Co.: Brit. Patent 815,934 (.rlriy 1, 1959). (2) Atanasiu. I.. Blurn, L., Popa, M., Bul. inrf. fiolitdinic Bucurpj/i 20, N o . 2. 103-8 ( I 958). (3) Brindley, P. B., Graham, A. R. (to Distillers Co.. Ltd.). Brit. Patent 810,530 (March 18, 1959). (4) California Research Corp., Ibid., 821,404 (Oct. 7 ; 1959). (5) Fidler, D. .4. (to Olin Mathieson Chemical Corp.), U. S. Patent 2,884,458 (Apr! 28, 1959). (6) Freidlin, L. Kh., Balandin, A. A . , others, Zhur. Priklad. Khirn. 32, 1600-4 (1959). (7) Gol’dfarb, .M. I.: Litvinenko, M. I., others, Russ. Patent 118,506 (March 10,
1959). Mononitrobenzene i s stored in these tanks at Cyanamid’s aniline manufacturing plant, Willow Island, W. Va. The fluid bed catalytic process utilizes a copper on silica catalyst
C. M., Megson, F. H. (to American Cyanamid Co.), U. S. Patent 2,891,094
Bechamp Reduction
Electrolytic Reduction
-4 continuous process was described by Gol’dfarb and others (7) for the production of aniline by the reduction of nitrobenzene with iron shavings in a suitable electrolyte in a Russian patent. T h e reactants are preheated and then passed through a suitable reactor. and the aniline is removed from the reaction vapors and reaction mass. Another Russian patent (21) gives a procedure for the preparation of pphenetidine from p-nitrophenetole by treatment Jcith iron filings. T h e reduction of 4-nitro-4’-aminodiphenyl sulfide to 4,4’-diaminodiphenyl sulfide by means of cast iron shavings and dilute hydrochloric acid was discussed by Zasosov and coworkers ( 2 4 ) .
Variables in electrolvtic ieduction ol‘ p-nitrophenetole to p-phenetidine LVCI c studied (2) using a lead anode and d copper cathode. and optimum conditions for this reduction \sere described. T h e electrolytic reduction of m-dinitrobenzene in the presence of sulfuric acid and copper sulfate, using a rotating lead cathode and lead anode. to yield 2.4diaminophenol, was reported by Subramanian and others (77).
Sulfide Reduction T h e only significant publication on the sulfide method of reduction was a patent issued to Latourette and others ( 7 7 ) on the reduction of crude m-chloronitrobenzene containing isomeric impurities by treatment with aqueous sodium hydrogen sulfide. The o- and $-isomers are thereby converted to soluble mercaptans and removed. T h e m-isomer yields m-chloroaniline, which is recovered,
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INDUSTRIAL AND ENGINEERING CHEMISTRY
(8) Hamilton, J. M., Spiegler, L. (to E. I . du Pont de Nemours 8: C o . ) , U. S. Patent 2,857,337 (Oct. 21, 1958). (9) Kagan. M . Ya., Grigoryan, 1:. S., Tsapko, I. M., Russ. Patent 118,505 (March 10, 1959). (10) Karkalits, 0. C., Jr., Vanderwaart,
lithium Aluminum Hyride Reduction T h e only other significant method of amination by reduction discussed in the published or patent literature was the lithium aluminum hydride method. Thiel and others (20) have described the use of this type of reduction to convert 3-thiazolines and A3-dihydro-rnthiazines to /?- and y-mercapto amines, I
through hydrogenation of the HC=Sgroup and hydrogenolysis of the bond between S and C-2. .4n extensive study \vas made by Olah (72) on the effect of catalysts in reducing nitrobenzenes and azobenzenes to hydrazobenzenes by means of lithium aluminum h>-dride. \.arious
(June 16, 1959). (11) Latourette, H. K.! Johnson, 0. H., Getz, J. W. (to Food Machinery and Chemical Corp.), Zbid., 2,894,035 (.July 7. 1959). (12) Olah, G. ,\., J . Am. Chem. ,S.ic. 81, 3165 (1959). (13) Polkovnikov, B. I)., Freidlin, L. K h . , Balandin, A. A , , Izuest. Akad. .Vuuk S. S. S. R., Otdel. Khim. >jTaiik 1959, pp. 1488-90. (14) Reinheckel, H., Tauber, G., .lonatrber. deut. Akad. W i s s . Berlin 1 , 43-4 (1959). (15) Scalera, M., Tomcufcik, -4. S., Hardy, W. B. (to .American Cyanamid Co.), E. S. Patent 2,879,274 (March 24, 1959). (16) Sobolev. Yu. P., Berezovskii, V. %f., Russ. Patent 118,129 (Feb. 20, 1959). (17) Subramanian: G. S., Udupa, H. V., Dey, B. B. (to Council of Scientific
and Industrial Research) Indian Patent 60,865 (April 4, 1959). (18) Suzuki, M., Yukugaku Z u ~ s h i 79, ~
286-90 (1959). (1 9) Terent’ev, A. P.. Preobrazhenskaya, M. N., Ge, B.-L., Khtm. ~ V Q Ui ~Proin. Q 4, 281-2 (1959). (20) Thiel! M., Asinger, F., others,
