INDUSTRIAL AND ENGINEERING CHEMISTRY
June 1952
’
1401
SUMMARY
OF STEAM-DISTILLED NITROXYLENES TABLE 111. COMPOSITION o-Xylene has been nitrated with a yield of 90% mononitro-+ DETERMINED BY VACUUM DISTILLATION xylenes using the following conditions:
Volume yo 1.2 45.6 17.0 33.6 1.4 1.2 100.0
Light ends 3-Nitro-o-xylene Mixed isomers 4-Nitro-o-xylene Residue Losses
-
(45.6) 3-Nitro-o-xylene = 45.6 4-Nitro-o-xylene = (33.6) 45.6
(100) 33.6 57‘6% (100) = 42.4% 33.6
+ +
PROPERTIES OF NITRO-0-XYLENES TABLE IV. PHYSICAL Property
3-Nitro-o-xylene
Densit g./ml. 31° 15” C. 30’ C,. Refractive index, nn 200 c. 25’ C. Boiling point, C. 760 mm.
8:
758.2 mm. 569 mm. 91 .Omm. 29 mm. 21 mm. Melting point,
1,1274 1.146 (f7)
..
1.5436 1.5416 248.3 240 ( 6 ) 247.6
....
172.5 136 ( 6 )
4-Nitro-o-xylene 1.1286
1 , iik’ (14)
....
1.5543 264.1 254 252.0
....
C.
The precision of the data was determined from nitrations conducted under identical conditions. Runs 16 and 28 give yields agreeing within 0.2%, but run 12, because of poor control, agreed within 1%. It is believed that the results are reproducible within 1%, but possibly greater variation is found under conditions giving low yields. REACTION BY-PRODUCTS
From each nitration a black, tarry residue remained in the steam distillation flask. From run 30 this amounted t o 12.2 grams. At 100’ C. the residue was a viscous liquid and a t room temperature it was a sticky, semisolid amorphous mass. Attempts t o crystallize dinitro compounds from this residue dissolved in several solvents were unsuccessful. SEPARATION OF ISOMERS
The mononitro compound from runs 2, 4, and 6 was combined and a 500-ml. sample was distilled at 88 mm. of mercury for 6.5 hours. The residue from the distillation was steam-distilled, giving 7 ml. of black, tarry residue much like that remaining from previous steam distillations. A distillation curve was prepared and the significant points were taken from it. The amounts of the various components are given in Table 111. The orientation was determined from the amounts of isomers separated. The amount of mixed isomers is rather large (17.0%), but even if t h e amounts of isomers in it were equal, its separation would make a difference of only 1.2% in the orientation reported. The orientation reported here is in substantial agreement with German industry as reported by Adams et al. ( 1 )and at variance with reports of previous workers (6,8,9). A center cut of product from the distillation of each isomer was redistilled under vacuum with a rejection of initial and final fractions. The physical properties of t h e purified materials were determined and are given in Table IV in comparison with other valdes reported in the literature. Crossley and Wren (6) prepared 3-nitro-o-xylene free from the 4-isomer by the conversion of 3nitro-o-xylidine. The pure compound melted sharply at 15’ C. They prepared a melting point curve for small amounts of the 4isomer in 3-nitro-o-xylene.
Sulfuric acid-o-xylene weight ratio Concentration of sulfuric acid, % Nitric acid-p-xylene mole ratio Temperature, C. Nitration time, minutes
2.15 79.4 1.16 25 30
The effect of changing these process variables on the yield is shown graphically. A new method of plotting contours of equal yields shows the interrelationship of sulfuric acid concentration and temperature; with more dilute acid higher temperatures can be used t o Becure equal yields. The orientation is found t o be 58% 3-nitro- and 42% 4-nitroo-xylene. LITERATURE CITED
Adams, D. A. W., Harrington, T., and Livingstone, A. Y . , I. G. Farbenindustrie, “Separation of o-, m-, and p-Xylene and Manufacture of Derived Nitroxylenes and Xylidines,” British Intelligence Objectives Sub-committee, F i n a l Rept. 1146. Batchelder, G. W., Nagle, W. M., Vyverberg, J. C., and Willis, J. M., U. S. Patent 2,400,904 (May 28, 1946). Brown, C. L., Smith, W. M., and Scharman, W. G., IND. ENQ.CHEM..40. 1538-42 (1948). Castner, J. B.,.’U. S. Patent 2,385,‘128(Sept. 18, 1945), 2,438,204 (March 23, 1948). Crossley, A. W., and Renouf, N., J . Chem. Soc., 95, 202-18 (1909). Crossley, A. W., and Wren, G. H., Ibid., 99,2341-5 (1911). Doumani, T. F., and Kobe, X. A , , IND. ENG.CHEM.,31, 257-63 (1939). Emerson, 0. H., and Smith, L. I., J. Am. Chem. Soc., 62, 141-2 (1940). Farmer, E. H., and Sutton, D. A., J . Chem. Soc., 1946, 10-13. Forziati, A. F., Glascow, A. B., Jr., and Willingham, C. B., J . Research Natl. B u r . Standards, 36, 129-36 (1946). Gillespie, R. J., and Millen, D. J., Quart. Rev. ( L o n d o n ) , 2, 277306 (1048). Groggins, P. H., editor-in-chief, “Unit Processes in Organic Synthesis,” 3rd ed., pp. 25, 66-71, New York, McGraw-Hill Book Co., 1947. Haun, J. W., and Kobe, K. A,, IND.ENQ.CHEM.,43, 2355-62 (1951). Jacobson, Oscar, Ber., 17, 159-62 (1884). Kobe. K. A,. and Levin. H.. IND. ENG.CHEM..42.352-6 (1950). Kuno, J. F.. Jr., Howell, W. C., Jr., and Star;, C: E., Jr.; Ibid., 40,1530-8 (1949). Nolting, E., and Forel, S., Ber., 18, 2668-81 (1885). Okie, J. P., and Roberts, L. M., Chem. Eng., 55, No. 10, 124-6 (1948). Patterson, T. S., McMillan, A., and Somerville, R., J . Chem. SOC.,125, 2488-90 (1924). RECEIVED for review July 16, 1951. ACCEPTED January 25, 1952. Presented before the Division of Industrial and Engineering Chemistry, Sixteenth Unit Process Symposium, a t the 120th Meeting of t h e AMEHICAN CHEMICAL SOCIETY, New York, N. Y.
Corrections I n the article on “Maturing and Bleaching Agents Used in Producing Flour” [IND.ENG.CHEM.,44, 95 (1952)l caption B of Figure 7 should have read “nitrogen trichloride” instead of “nitrogen dioxide.” I n the acknowledgment on page 100 t h e first name mentioned should have been G. C. Thomas. C. G. HARREL
. . .. . , .
In the paper “Soiling and Soil Retention in Textile Fibers. Cotton Fiber-Grease-Free Carbon Black Systems” [Compton, Jack, and Hart, W. J., IND.ENG.CHEM.,43, 1564-9 (1951)], the average particle sizes of the carbon blacks were erroneously stated t o be in microns instead of the correct units, millimicrons. JACKCOMFTON
