Amination by Reduction mg
JESSE WERNER, AND FILM
GENERAL A N I L I N E
CORPORATION, GRASSELLI, N. 1.
D
Ilaiiey nickel (one to three times the weight of the nitro compound). In a comparative study, the mercapto group was found to have the most deleterious effect and to require the most massive doses of catalyst. The simultaneous reduction of the nitro groups and replacement of the chloro group by hydrogen in 2,4-, 2,6-, and 3,5dinitrochlorobenzene on treatment with hydrogen a t 75 to 100 pounds per square inch gage and 20' to 40" C. in the presence of Raney nickel and excess alkali to form m-phenylenediamine B~CHAMP REDUCTION has been patented by Kamlet (33), The alkali is added during the reaction in order to neutralize liberated hydrochloric acid. In so far as the BBchamp method of reduction (iron and dilute -4n advantage of this process is the utilization of a by-product acid) is concerned, Geigy (17)has patented the reduction of 2,2eutectic mixture of 2,4- and 2,6-dinitrochlorobenzene. The bis(p-nitrophenyl>l,l,l-trichloroethane to the corresponding yields for the different isomers vary from about 69 to 84% of tiis(p-aminophenyl) derivative using iron and dilute acetic acid theory. in the presence of ethanol as a solvent at 70" C. McGhie et al. Weizmann (66) has studied the catalytic reduction of the B($8)have reported the reduction of p-nitrosalicylic acid to the diethylaminoethyl ester of 2-chloro-4-nitrobenzoic acid under therapeutically important p-aminosalicylic acid using ferrous varioue conditions. Reduction with palladium on barium sulfate sulfate in water. A similar reduction of 9-amino-1-nitroacridone in ethanol results in the formation of the hydroxylamino derivato 1,9-diaminoacridone hap been described by Hampton and tive. Changing the solvent to ethyl acetate gives the azoxy Magrath (99). compound. The use of palladium in acetyl-N,N-diethylethanolamine gives a mixture of the hydroxylamino and amino comCATALYTIC REDUCTION pounds. Reduction of the free acid or ethyl ester in ethyl acetate in the presence of palladium on barium sulfate gives the Vltrious aspects of catalytic reduction have been studied durcorresponding amine, whereas changing the solvent to isopropyl iug the period covered by this =view. Fujita (U) has described alcohol results in a replacement of the chloro group to form pthe reduction of nitrobenzene, o-nitrophenol, nt-nitrophenol, and aminobenzoic acid. This latter product is also formed when the p-nitrophenol to the corresponding amines using hydrogen and a sodium salt of the free acid is redhced in water. reduced nickel catalyst in absolute alcohol at 1380 to 1440 The catalytic hydrogenation of l-nitro-2,3-naphthalenedipounds per square inch gage at a temperature of 100" C. Tomcarboximide to the corresponding 1-amino derivative in the kuljak (62)has reported the hydrogenation of o-nitroaniline to presence of platinum oxide in ethyl acetate is reported by Crow *phenylenediamine in the presence of Raney nickel in a yield and Drew (I0). The reduction of 3-nitroso-2-phenyl-1-ethylof 90 to 95% of theory. Bhate et nl. (8)have described a similar indole in ethanol with platinum oxide to give the 3-amino comreduction of p-nitrosalicylic acid to p-aminosalicylic acid. Corpound has been described (29). Borrows et a2. (6) have found responding reductions, but using platinum oxide as the ctttalyst, that catalytic hydrogenation of 5-[3,5-dinitro4(p-hydroxyphehave been reported for both the free acid (I) and the methyl noxy)benzyl]hydantoin in acetic acid using palladium on charcoal eRter ( I d ) . Hydrogenation of l,l-dichloro-2,2-bis(3-nitro-4-methoxy- gives t,he corresponding diamine in 70% yield. Weisblat and Lyttle (66) have reported that the reduction of ethyl a-nitro-ppheny1)ethylene (dehydrohalogenated dinitromethoxychlor) in (3-hdole) propionate over Raney nickel at 100' C. followed by ether over Raney nickel at 40 pounds per square inch gage to the hydrolysis with 20% caustic soda gives an 87% yield of dlcorresponding diamino compound was reported by Shirley et al. tryptophan. (49). Icke et al. (300)have given complete process details for the Lambooy (868) has described the catalytic hydrogenation of 4,sreduction of m-nitrobenzaldehyde dimethyl acetal to the amine diethyl-2-nitroaniline over a platinum-zirconium catalyst in in methanol using hydrogen and Raney nickel, in a yield of ethanol a t 60 O C. to give 4,5-diethyl-o-phenylenediamine. The 07 to 78% of theory. Beech and Legg ( 8 ) have reported the reduction of nitrophthalidylalkanes has been patented by catalytic reduction of B-nitro-4-hydroxy-2-naphthoicacid to the (6.9)using a process which comprises catalytic hydrogenalJllyot corresponding amino compound (carboxy-yacid) using Raney tion ifi the presence of a noble metal catalyst using a mineral or nickel and hydrogen. strong organic acid-for example, palladium chloride on charcoal Gill et al. (f8)have described the reduction of symmetrical in ethanol and hydrochloric acid at 70' to 80" C . a t 50 pounds trinitro derivatives of benzene, toluene, ethylbenzene, chloroper square inch gage. benzene, anisole, phenetole, isobutoxybenzene, diphenyl ether, Condit (8)has published a somewhat detailed discussion of the phenylethyl alcohol, and phenylethyl acetate to the corresponding continuous reduction of nitrobenzene and nitroxylene in the triamines using hydrogen, Raney nickel (15% of the weight of preReiice of molybdenum sulfide on active carbon. These reducthe nitro compound), and ethyl acetate (2000% of the weight of tions may be carried out a t atmospheric pressure, but the catathe nitro compound), at a pressure of 40 poun'ds per square inch lyst gradually loses activity by becoming coated with tarry congage. Similar reductions of the 2,4,6-trinitrophenol ethers have densation products. For nitrbbenzene the optimum conditions been patented by Imperial Chemical Industries, Ltd. (81). are over 300" C., a pressure of 400 to 500 pounds per square inch The poisoning effect of organic sulfur compounds on Raney gage, and a large excess of hydrogen. Under these conditions, nickel catalyst is well known. Fel'dman (IS) reports that this space rates up to 1.5 volumes per volume per hour can be used can be overcome in nitro compounds containing mercaptan, and the catalyst is stable. However, under the same condition8 sulfide, sulfone, and disulfide linkages by using large excesses of
URING the past 12 nioiiths considerable work has been published with regard to the chemical and engineering phases of the unit process, amination by reduction, Although thie has been varied in approach, catalytic reduction hiis, as usual during the past decade, received the lion's share of attention. The other methods have been more or less neglected, particulrtrly laboratory work.
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INDUSTRIAL A N D ENGINEERING CHEMISTRY
nitroxylene uiidergocs some thermal decomposition and the catalyst becomes coated with carbonaceous material. Batch runs indicate that the catalyst is active down to as low as 232" C. a t 3000 pounds per square inch gage. The increased pressure ypreads the range between the temperatures of rapid hydrogenation and decomposition. Scharmann and Nelson (46) have patented a method of continuously reducing an aromatic nitro compound to the corresponding amine in a reaction zone which contains a plurality of spaced beds of catalyst and in which the nitro compound, hydrogen, and water are introduced a t the top and hydrogen is passed in a t spaced points betweeq the catalyst beds. This accelerates the vaporization of water, which absorbs heat and maintains a temperature between 205' and 260' C. The pressure is kept above the vapor pressure of water a t the reaction temperature, usually a t 500 to 5000 pounds per square inch gage, These conditions are also claimed specifically for nitroxylene. The preferred catalyst is molybdenum sulfide on charcoal. Rockett and Wiitmore (43) have described the catalytic reduction of dinitroneopentane, (CH&C( CH2N0&, to the corresponding diamine in 67% yield using Raney nickel in alcohol at 60" C. and 1000 pounds per square inch gage. As a byproduct they obtained 5% of a,a-dimethylmalonamide. Haury (24) has patented the formation of aliphatic amino alcohols, containing a three-carbon chain between the amino and hydroxy groups, by treating 1,a-diazines with hydrogen and water at 100" to 150' C. and 800 to 1000 pounds per square inch gage. Haury (23) has also been granted another interesting patent involving the catalytic reduction of pyrimidine or its derivatives with hydrogen and ammonia (or amines) to produce substituted trimethylenediamines in good yield, with monoamines as byproducts. Thus, the treatment of 2,2,4,4,6-~entamethyltetrahydropyrimidine with hydrogen and ammonia over Raney nickel a t 1000 pounds per square inch gage and 150"to 175' C. gives 77.5 to 79y0 of 2,4-diamino-2-methylpentaneand 61 to 69% isopropylamine. Reaction of 2,2,4,4,6-~entamethyltetrahydropyrimidine with hydrogen and isopropylamine over Raney nickel a t 500 to 600 pounds per square inch gage and 150' to 170' C. gives 2,4-diamino-2-methylpentane. Condit and Haynor (9) have published a study of the explosive decomposition of nitrobenzene and nitrotoluene under conditions approaching those of commercial hydrogenation. The minimum temperatures are about 356' C. for nitrobenzene and 308" C. for nitroxylene and are relatively independent of the pressure of the surrounding gas. They are the same in hydrogen as in methane and are unaffected by the presence of various steels and of activated carbon. The decomposition temperature of nitroxylene is somewhat lowered by the presence of 5 to 15% dinitroxylene. Prolonged heating of nitroxylene below its decomposition point gives rise to resins; but nitrobenzene is somewhat more stable. Small amounts of the corresponding amines lower the decomposition temperature, but amine concentrations above 25% prevent explosive decomposition, giving resinous masses instead. The decomposition temperature of nitroxylene is, however, lowered markedly by the presence of hydrogen and molybdenum sulfide on active carbon because of the initiating effect of the exothermic hydrogenation of nitroxylene. Houghton and Lowdermilk (28) have described a new nickel catalyst effective for the reduction of nitroxylene. The catalyst is made by reducing nickel oxide a t 215" to 300' C. by means of the effluent from the hydrogenation of nitroxylene with a previously prepared catalyst. The effluent must not contain more than 5% nitroxylene based on total organic material and must be below its dew point. Billica and Adkins ( 4 ) have presented details for the production of W-6 Raney nickel catalysts which have high contents of aluminum and absorbed hydrogen and are effective in low temperature hydrogenation. Rosenblatt (44) has patented supported platinum and palladium catalysts which art) claimed to be effective' for the reduction of nitro compounds.
Vol. 42, No. 9
These are produced by hydrolyzing ttqueous solutions of COIIIpounds containing these metals in their divalent state. This is done in the presence of a carrier that is a water-insoluble dohydrated basic oxide of a nonprecious metal from groups I11 t o VI11 of the Periodic System. The catalyst is precipitated on thc carrier surface by pH and heat and then activated. Several patents (26,60,61) have been issued on the hydrogeruction of aliphatic nitriles or polynitriles to primary aminert by treatment with hydrogen in tho presence of nickel or cobalt catulysts (such as Raney nickel) and water-soluble alkali, under pressure. A patent has been issued to Sharples Chemicals (48) covering the reductive amination of aldehydes and ketones with hydrogen and ammonia or amines. Better yields are claimed because of slow addition of the oxo compounds. Goldberg and Teitel (20) have patented a similar treatment of p-ionone with ammonia and hydrogen in the presence of methanol and Ranev nickel a t 150' C. and 2000 pounds per square inch gage to g i v ~ 8-dihydroionylamine.
SULFIDE REDUCTIONS Hodgson and Ward (255)have published a rather comprehensive study of the treatment of dinitrobenzenes and dinitronaphthalenes with alkali sulfides. They have found that the following general reactions predominate: o-dinitrobenzene + bis( 2-nitrophenyl)sulfide m-dinitrobenzene 3 m-nitroaniline -nitroaniline pdinitrobenzene 4 4,4'-dinitroazobenzene 1,2-dinitronaphthalene -+ 1,4dinitronaphthalene 4 bis(4-nitro-1-naphthy1)sulfide 1,5-dinitronaphthalene + 5-nitro-1-naphthylamine 5nitro-1-naphthalenethiol 1,6-dinitronaphthalene -+ 5-nitro-2-naphthylamine 5. nitro-2-naphthalenethiol 2,7-dinitronaphthalene 7-nitro-2-naphthylamine 7nitro-2-naphthalenethiol
+
bis(2-nitro-1-naphthyl ysulfide
-.
+ + +
A patent (60) has been issued to Zimmerman covering the selective reduction of the 2-nitro group in 2,4-dinitrophenols (such as the 6-chloro derivative) by means of alkali metal or ammonium sulfides (or polysulfides) in alkaline medium. Yoshida et al. (69) have reported the reduction of p-nitrobenzoyl-L(+)glutamic acid to the corresponding amino derivative by meana of ammonium sulfide. Oehlschlaeger and MacGregor (40) have described the reduction of 7-nitrofluoren-9-one-2-carboxylic acid with ammonium sulfide in aqueous ethanol to give the amine. A Swiss patent (B7) has been issued to Hoffmann-La Roche covering the reduction of 2,4-diamino-3aitropyridine to 2,3,4-triaminopyridine by means of sodium sulfide. ELECTROLYTIC REDUCTION Dey el al. (11) have described the electrolytic reduction of ochloronitrobenzene to m-chloro-p-aminophenol using a copper cathode, a lead anode, a catholyte composed of the starting material, xylene, and 30% sulfuric acid and an anolyte consisting of 30% sulfuric acid. Copper sulfate is used as a catalyst, the temperature is 50' to 55' C., and the current density is 5.99 amperes per square dm. Yields of 29.1% of m-chloro-p-aminophenol and 24% of o-chloroaniline are claimed. The use of lead as a cathode gives a, higher yield (34.6%) of o-chloroaniline. The effect of dielectric constant of the solvent in electroorganic reductions has been studied by France and Turk (14). They found that lowering of the dielectric constant when the reducible group forms the negative part of the dipole reduces the efficiency of reduction. The reason for this behavior is that lowering of the dielectric constant increases the molecular orientation which forces the reducible group away from the cathode. Sahmhi et al. (46) have patented the electrolytic reduction of chloromethylnitrotoluene to form xylidine, Nitrotoluene is
INDUSTRIAL AND ENGINEERING CHEMISTRY
September 1950
treated with bis(chloromethy1)ether in the presence of sulfuric acid to give chloromethylnitrotoluene (Stephen, Short, and Gladding reaction). This intermediate is then reduced electrolytically to xylidine, using ethyl and 10% sulfuric acid as the catholyte and 10% Sulfuric acid as the anolyte. The cathode may be lead, zinc, or copper, the anode may be lead, and the diaphragm is made of kaolin. McMillan ($99)has patented the electrolytic reduction of nitro aliphatic compounds of the following general constitution: RRfC(N02)CH20H, where R is -CHa, -C2H,, or -CH2OII and R' is H, -CHr, -Ca&, or -CHaOH. The catholyte is 10% hydrochloric acid or 25% sulfuric acid, the current density is about 0.2 ampere per square cm., the cathode is polished lead, and the temperature is 65" to 85" C. The yields of the corresponding amines are given as about 81 to 94% of theory. A thorough study of the cathodic reduction of trichloronitromethane has been described by Brintzinger et al. (6). The cathodes tested were platinum, silver, copper, nickel, lead, tin, and brass, using solutions of 1 to 70% sulfuric acid and methyl, ethyl, propyl, butyl, and amyl alcohols a t temperatures of 0" to 25" C. At low sulfuric acid concentrations, reduction proceeds through methylhydroxylamine to methylamine. At concentrations of sulfuric acid above 20%, trichloronitrosomethane is formed first. This is reduced to dichloronitrosomethane, which then rearranges to dichloroformoxine, C12C=NOH. Korshunov d al. ($66) have dcscribed analytical procedures for determining nitrobenzene polarographically in aqueous solutions, in aniline, in benzidine, and also when mixed with dinitrobenzene. Vahshteh (6.6)has also reported a similar polarographic determination of 1-nitronaphthalene in 1-naphthylamine. A polarographic study of nitrobenzene has been carried out by Korshunov and Kirillova (34), who have brought forth evidence to indicate that reduction of nitrobenzene at the dropping mercury electrode takes the following course:
+ CsH6N0 2H+ + 2e t C~&NOZHI CdIsNO + HtO + 2H+ + 2e CeHoNHOH C&NHOH + 2H + 2e CsHsNH* + HnO
C&HsNO2
-
+
+
+
Pearson (41) has studied the reduction of nitroresorcinols at the dropping mercury electrode and reported that the reduction to the corresponding amines is complete in one stage a t all hydrogen ion concentrations.
MISCELLANEOUS REDUCTIONS Schofield (47)has described the reduction of 2 4 enitrobenzoy1)pyridine to the corresponding amine using stannous chloride in hydrochloric acid. Similar reductions have been reported for 5,b-dimethoxy 8 nitroquinoline (68),9 -amino- 4 nitroacridhe (99), and 3-amino-7-nitro-9(10H)acridone (19). Reductions with zinc and mineral acids have been reported for p-nitmsalicylic acid ( 1 ) and brominated 8-nitro-p-cymenes (49). Joshi and Shah (88)have described the reduction of various nitro compounds to the corresponding amines in 50 to 75% yield using sodium hydrosulfite in dilute sodium hydroxide solution. Gaudry and Keirstead (16)have found that treatment of chloronitrobenzenes with sodium arsenite in methanol gives rise to the Corresponding azoxy compounds. Hallie (gf)has patented the continuous reduction of nitrobenzene to hydrazobenzene using alkali amalgam together with carbon or iron as a catalyst, in the presence of aqueous solvents such as 70% ethanol. The preferred catalyst is carbon, which may be present as graphite, coke, or activated carbon, provided the iron content is below 1%. Buckley and Ray (7) have published some interesting studies involving reductions with carbon monoxide at rather high temperatures and superatmospheric pressures. Nitrobenzene, when treated with carbon monoxide at 250' C. and 45,000 pounds per square inch gage, gives a good yield of azobenzene and carbon dioxide. Nitrosobenzene, a t 150' C. and 45,000 pounds per
- -
-
1663
square inch gage, similarly gives azobenzene together with tarry by-products. Azoxybenzene, at 200" C. and the same pressure, is also reduced to azobenzene in good yield. Phenylhydroxylamine, treated exactly as azoxybenzene, gives rise to both azobenzene and aniline. These workers also report that aliphatic nitro compounds could not be similarly reduced below their decomposition points. The only review paper concerning this unit process, other than the preceding paper of this series (by), which appeared during the 12-month period covered by the present review was that by Lukashevich (57).
LITERATURE CITED (1)Aktiebologet Ferrosan, Brit. Patent 823,114 (May 12, 1949). 12) Beech, W.F., and Legg, N., J . Chem. Soc., 1949,1887-9. ( 3 ) Bhate, D. S., Panse, T. B., and Venkataraman, K., Proc. Indian A&. Sci., 29A,196-202 (1949). (4) Billica, H. R., and Adkina, H., Org. Sunthew, 29,24-9 (1949). (5) Borrows, E.T.,Clayton, J. C.. and Hems, B. A., J . Chem. Soc., 1949,Suppl. Issue, No.1, 9199-204. ( 8 ) Brinteinger, H., Ziegler, H. W., and Schneider, E., 2. Elektrochem., 53,109-13 (1949). (7)Buckley, G. D.,and Ray, N. H., J. Chem. Soc., 1949,115443. (8) Condit, P. C., IND.ENQ.CHEM., 41, 1704-9 (1949). (9) Condit, P. C., and Haynor, R. L., Ibid., 41,1700-4 (1949). (10) Cross, B. E.,and Drew, H. D. K., J . Chem. Soc., 1949,1532-6. (11) Dey, B. B., Maller, K., and Pai, B. R., J . Sci. Ind. Research (India), 8B,NO.11, 206-8 (1949). (12) Drain, D. J., Martin, D. D., Mitchell, B. W., Seymour, D. E., and Spring, E. S.,J. Chem. Soc., 1949,1498-503. (13) Fel'dman, I. W., D o k W y A M . Nauk S.S.S.R., 65, 857-60 (1949). (14)France, W. G., and Turk,A., J. Phys. & Colloid Chem., 53,48Z 6 (1949). (15) Fujits, S.,Mem.COX Sci. Kyoto Imp. Univ., 23A,431-8 (1942). (18) Gaudry, R., and Keirstead, K. F., Can. J. Rssearch, 27B,8908 (1949). (17) Geigy A.43.. J. R., Swiss Patent 258,140 (April 16, 1949). (18) Gill, J. E., MacGillivray, R., and Munro, J., J . Chem. Soc., 1949.17534. - ..., - . - - -. (IS) Goldberg, A. A,. and Kelly, W. (to Ward, Blenkinsop and Co., Ltd.), U.S. Patent 2,493,191(Jan. 3,1950). (20) Goldberg, M. W.,and Teitel, 5. (to Hoffmann-La Roche, Ino.), U. S. Patent 2,483,381(Sept. 27, 1949). (21) Hallie, G. (to Directie van de Staatmijnen in Limburg), U. S. Patent 2,488,358(Oct. 25,1949). (22)Hampton, A,, and Magrath, D., J . Chem. Soc., 1949, 1008-11. (23) Haury, V. E. (to Shell Development Co.), U. S. Patent 2,486,648(Nov. 1,1949). (24) Haury, V. E. (to Shell Development Co.), U. 8. Patent 2,497,548(Feb. 14,1950). (25) Hodgaon, H. H., and Ward, E. R., J . Char.Sm., 1949,1316-17. (28) Hoffmann-La Roohe and Co. A.-G., F., Swias Patent 244,837(June 16,1947). (27)Zbid., 260,573 (July 16,1949). (28) Houghton, A. S., and Lowdermilk, F. R. (to Allied Chemical and Dye Corp ), U.S. Patent 2,489,886(Nov. 29,1949). (29) Huang-Hsinmin and Mann, F. G., J . C h . Soc., 1949,2903-11. (30) Icke, R. N., Redemann, C. E., Wisegarver, B. B., and Alles, G. A.. Ora. Syntheses, 29,8-8 (1949). (31)Imperial Chemical Industries, Ltd., Brit. Patent 826,360 (June 27,1949). (32)Joahi, G.G.,and Shah, N. M., Ciment Sci. (India), 18, 73-4 (1949). (33) Kamlet, J. (to Boyle-Midway, Inc.), U. 9. Patent 2,484,044 (March 8,1949). (34)Korshunov, 4. A., and Kirillova, A. S., J. Gen. Chem. (U.S.S.R.),18,785-92 (1948). (35)Korshunov, I. A., Ryabov, A. V., Sazanova, L. N.,and Kirillova, A. S., Zuaodukaya Lab., 14,514-22 (1948). (38) Lambooy, J. P., J. Am. Chem. Soc., 71,3768-7 (1949). (37) Lukashevich,V. O.,Uspekhi Khim., 17,892-709 (1948). (38)McGhie, J. F.,Morton, C., Reynolds, B. L., and Spence, J. W., J. SOC.Chem. Ind. (London), 68,328-9 (1949). (39)McMillan, G. W. (to Commercial Solvents Corp.), U. 9. Patent 2,485,982(Oct. 25,1949). (40)Oehlachlaeger, H. F., and MacGregor, I. R., J . Am. Chem. Soc., 71, 3223-5 (1949). (41)Pearson, J., Trans. Faraday SOC.,45,199-203 (1949). (42)Qvist, W.,Acla Acad. Aboensh, Math. et Phys., 16,1-14 (1948). (43) Rockett. J., and Whitmore, F. C., J . Am. Chem. SOC.,71,324950 (1949).
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INDUSTRIAL AND ENGINEERING CHEMISTRY
(44) Rosenblatt, E. F. (to Baker and Co., Inc.), V. S. Patent 2,475,155(July 5,1949). (45)Sahashi, K., et al. (to Rikagaku Kenkyojo), Japan. Patent 172,795(May31.1946). (46) Scharmann, W. G., and Nelson, J. J. (to Standard Oil Development Co.), U.S. Patent 2,451,245(Sept. 6, 1949). (47)Schofield, K., J. C h m . SOC.,1949,2393-9. (48) Sharples Chemicals, Inc., Brit. Patent 615,715(Jan. 11, 1949). (49) Shirley, D.A, Goreau, T. N., and Eiseman, F. S.,Jr., J . Am. Chem. Soc., 71,3173-5 (1949). (50) Sillar S. 8. r. l., Italian Patent 431,671 (March 2,1948). (51) Soci6t6 des usines chimiques RhBne-Poulenc, French Patent 866,545 (Aug. 18,1941). (52)Tomkuljak, D., Chenb. Zvesti, 2, 114-19 (1948).
Vol. 42, No. 9
(53) Ullyot, G . E. (to Smith, Kline and French Laboratories), W. S. Patent 2,450,105(Aug. 30, 1949). (54)Vainshtetn, Yu, I., Zavodslzaya Lab., 14,517-19 (1948). (55) Weisblat, D. I., and Lyttle, D. A., J. Am. Chem. SOC.,71,309781 (1949). (56)Weiemann, A., Ibid., 71,4154-5 (1949). (57)Werner, J., IND.ENQ.CREM.,41,1841-6 (1949). (55)Williamson, T. A., Brit. Patent 623,789 (May 23,1949). (59)Yoshida, S., Imaki, K., and dkagi, S., J . Pharm. Soc. Jopan. 69,457-8(1949). (60)Zimmerman, B. G. (to General Aniline and Film Gorp.), C S. Patent 2,464,194(March 8,1949). RECEIVED June 19, 1950.
AM M0N 0LYSlS DE NEMOURS 8 COMPANY, WILMINGTON, DEL.
R
ECENT development w involving the unit process ammonolysis have heen concerned with: (1) modification and broadening of the application of the reaction of ammonia and hydrocarbons Iwding to nitriles; (2) the use of high pressures in the manufacture of amines through a modified oxo process; (3) numerous applications of the reaction of ammonia and various functionally substituted organic molecules. Mechanism and kinetic studies have been concerned with the catalytic effect of Bodium in the ammonolysia of styrene and the reaction of ammonia with aldehydes and ketones. The problems of separating reaction products and devising continuous procedures for carrying out the reaction continue to receive the attention of investigators. This review has not been limited to ammonolysis in the narrowest sense but has been extended to include amination and reactions involving ammonia and amines in general.
supported on alundum, 6ti% of the methylcyctohexane was attacked, with 44 mole % being converted to benzonitrile. The reaction mixture consisted of 2 moles of ammonia, 1 mole of methylcyclohexane, and 150 moles of air. The reaction was carried out a t 440" C.with a space velocity of 2400 per hour. The catalyst contained 11 .4y0 vanadium, 3.9% molybdenum, and .034% phosphorus. This procedure is applicable to the preparation of aromatic nitriles from aromatic and substituted aromatic hydrocarbons. Examples appear in Table I. Aliphatic nitriles are prepared from olefins by a similar procedure (IO). The reaction of 2-methylpropene with ammonia and air in the ratios of 1 mole of hydrocarbon to 3 moles of ammonia and 110 moles of air results in a yield, based on the hydrocarbon introduced, of 28 mole yo acrylonitrile and 26 mole % acetonitrile. The reaction was carried out a t 485" C . with a space velocity of 3000 per hour. Teter (39)reports that sodium is effective in promoting reduced cobalt and nickel oxide catalysts in the preparation of nitriles by reacting olefins and :mimonia. The yield, based on the olefin feed, of nitrogen-containing products was increased from 11.2% with a catalyst wntaining 0.77% sodium to 36.3% when the sodium content was increased to 2.96%. The sodium is supplied to the catalyst ronipoqition in the form of the acetate or hydroxide. Isobutyronitrile has been prepared by the reaction of amiiioiiis and isobutylene oxide over a catalyst consisting of copper on alumina or silver supported on a combination of silica and alumina (98). The yield based on the olefin oxide charged is 46 mole yo with the latter catalyst. The reaction is effected at approximately 800' F. at atmospheric prewure. The contact time is 1.5 seconds. n-Butyrolnitrile results from the reaction of n-butyl alcohol and ammonia over a molybdenum oxide-alumina catalyst. A contact time of 0.5 second is used with a temperature of 820" F. Two moles of ammonia are used with each mole of alcohol (6).
NITRILES The procedures for the manufacture of nitriles by the direct ammonolysis of olefins and alkyl aromatic hydrocarbons previously reported by Denton, Bishop, and Marisic have been extended to include additional hydrocarbon materials as well as alkyl thiophenes and primary alcohols (13). Originally catalysts for this reaction were limited to the oxides of molybdenum, tungsten, phosphorus, and vanadium preferably supported on activated alumina; now metal salts of these materials have been proposed-for example, iron tungstate, ferric molybdate (Id), nickel and cobalt phosphate (IS, I 4 ) , and uranyl molybdate (16). The preparation of nitriles through the vapor phase ammonolysis of mono-, di-, and trimethylcyclohexenes with catalysts consisting of the oxides of molybdenum, tungsten, and vanadium supported on activated alumina is reported (30). Denton (12) emphasizes the importance of carrying out this reaction of ammonia and alkyl hydrocarbons at temperatures in the range of 975' to 1025 O F. in order to obtain maximum conversions to nitriles and to avoid Ion7 yields based on ammonia, due to decomposition of ammonia in contact with the catalyst. Decomposition ww found to he appreciable at 1075 " F. Table 1. Nitriles via Ammonolysis of Alkyl Aromatic Hydrocarbons in Presence of Oxygen (7 7) By adding air to the reaction mixture, Mole c7. ..___ YieldErchak (16) and Cosby (10) have Moles Mole8 (Based on effected an appreciable improvement in NHs/Mole Air/Mole Space Starting TQIII~,., Velocity Msterial Startinr: Starting Starting yield in this type reaction over previous Material Material Materisl a C. per Hour Product Attacked) investigators. In the vapor phase amToluene 2.0 75 450 2150 Benzonitrile 75 200 465 2260 Chlorobenzortitrile 47 monolysis of methylcyclohexane (18) r?g?$zFluene 3 . 06 BO 440 2700 Terephthdonitrile 26 over a catalyst comprising the oxides of p-Toluonitrile 22 vanadium, molybdenum, and phosphorus
