Organic Syntheses Part 15

Quinone may be prepared by the oxidation of aniline with dichromate or manganese dioxide and sulfuric acid.[1] This is a more feasible commercial method than the one given.

However, the oxidation of hydroquinone is more rapid and convenient and, hence is more desirable for use in the laboratory.

Various materials have been oxidized by chemical means to give quinone: they are quinic-acid,[2] hydroquinone,[3] benzidine,[4]

_p_-phenylenediamine,[5] sulfanilic acid,[6] _p_-phenolsulfonic acid,[7] arbutin,[8] aniline black,[9] and the leaves of various plants.[10] Quinone is also formed by several other methods: by the fermentation of fresh gra.s.s;[11] by the action of iodine on the lead salt of hydroquinone;[1b] by the decomposition of the compound, C6H4<.>2CrO2Cl with water;[2b] by the action of sulfuric acid on phenol blue;[3b] by the electrochemical oxidation of aniline,[4b] hydroquinone[5b] or benzene;[6b] by the catalytic oxidation of benzene.[7b]

[1] Jahresb. 1863, 415; Ber. 10, 1934, 2005 (1877); 16, 687 (1883); 19, 1468 (1886); 20, 2283 (1887); 31, 1524 (1898); Ann.

200, 240 (1880); 215, 127 (1882).

[2] Ann. 27, 268 (1838).

[3] Ann. 51, 152 (1844) j Am. Chem. J. 14, 555 (1892).

[4] Jahresb. 1863, 415.

5 Jahresb. 1863, 422.

6 Ann. 159, 7 (1871); Ber. 8, 760 (1875).

[7] Ber. 8, 760 (1875).

[8] Ann. 107, 233 (1858).

[9] Ber. 10, 1934 (1877); 34, 1285 (1901).

[10] Ann. 89, 247 (1854); Ber. 34, 1162 (1901).

[11] Ber. 30, 1870 (1897).

[1b] Ber. 31, 1458 (1898); Am. Chem. J. 26, 20 (1901).

[2b] Ann. chim. phys. (5) 22, 270 (1881).

[3b] Ber. 18, 2915 (1885); 21, 889 (1888).

[4b] D. R. P. 109,012; Frdl. 5, 664 (1900); D. R. P. 117,129; Frdl.

6, 112 (1901); J. Soc. Dyers and Colourists, 36, 138 (1920).

[5b] D. R P. 117,129; Frdl. 6, 112 (1901).

[6b] D. R. P. 117,251; Frdl. 6, 109 (1901); U. S. Pat.

1,322,580 (1919); C. A. 14, 287 (1920); Rev. produits chim.

21, 219 (1918); 21, 288 (1918).

[7b] U. S. Pat. 1,318,631 (1919); C. A. 14, 70 (1920).

XXIII

SODIUM _p_-TOLUENESULFINATE

2CH3C6H4SO2Cl + 3Zn--> (CH3C6H4SO2)2Zn + ZnCl2 (CH3C6H4SO2)2Zn + Na2CO3--> 2CH3C6H4SO2Na + ZnCO3

Prepared by FRANK C. WHITMORE and FRANCIS H. HAMILTON Checked by J. B. CONANT and PAUL ALLEN, JR.

1. Procedure

FIVE HUNDRED grams of technical _p_-toluenesulfonyl chloride are ground in a mortar to break up all lumps. Three liters of water are placed in a 12-l. crock provided with a large bra.s.s stirrer and a tube for pa.s.sing steam directly into the liquid. Dry steam is pa.s.sed into the water until the temperature reaches 70'0. The steam is then shut off and 400 g. of zinc dust (90 to 100 per cent pure) is added.

The sulfonyl chloride is then added in small portions by means of a porcelain spoon. The addition takes about ten minutes.

The temperature rises to about 80'0. Stirring is continued for ten minutes after the last of the chloride has been added.

Steam is then pa.s.sed into the mixture until the temperature reaches 90'0. If it is heated any hotter, b.u.mping takes place.

The steam is shut off, and 250 cc. of 12 _N_. sodium hydroxide solution is added. Finely powdered sodium carbonate is then added in 50-g. portions until the mixture is strongly alkaline.

The mixture froths considerably, but this causes no trouble unless too small a crock is used. The stirrer is loosened and the crock is removed. The mixture is filtered by suction in a large funnel.

The filtrate has a volume of about 4.5 l. The cake of unchanged zinc dust and zinc compounds is transferred to a 3-l. battery jar and placed under the stirrer, and the latter is clamped in place.

Water (750 cc.) is added, the stirrer is started, and steam is pa.s.sed in until the mixture starts to froth too violently.

The steam is then shut off, but the stirring is continued for ten minutes. The mixture is filtered and the filtrate is added to the main solution in a large evaporating dish.

The liquid is evaporated over a large burner to a volume of about 1 l., or until a considerable crust forms around the edges.

The mixture is then cooled. Large, flat, transparent crystals separate.

The thoroughly cooled mixture is filtered by suction, and the crystals are air-dried until efflorescence just starts.

They are then bottled. The product is CH3C6H4SO2Na<.>2H2O. Yield 360 g.

(64 per cent of the theoretical amount). Careful acidification of the mother liquor with dilute hydrochloric acid yields 15 g.

of the free sulfinic acid.

2. Notes

The free sulfinic acid may be prepared by dissolving the sodium salt in cold water and carefully acidifying the solution with hydrochloric acid.

An excess of the latter must be avoided, as it dissolves the acid to a certain extent. The sulfinic acid is difficult to dry without partial conversion into the sulfonic acid.

3. Other Methods of Preparation

Toluenesulfinic acid and its salts have been prepared by three general methods: (1) The reduction of the sulfonyl chloride.

The reagents which have been used for this are sodium amalgam,[1] zinc dust in alcohol or water,[2] sodium sulfite,[3] sodium sulfide,[4]

pota.s.sium hydrosulfide[5] (the thio acid being first formed) and sodium a.r.s.enite.[6] (2) From toluene by the Friedel and Crafts reaction, using either sulfur dioxide and hydrogen chloride[7]

or sulfuryl chloride.[8] (3) From _p_-toluidine by diazotization and subsequent treatment with sulfur dioxide and finely divided copper.[1b] The compound has also been obtained in certain reactions which, however, would not be suitable for preparative work; thus it is formed by hydrolysis and reduction of certain thio derivatives[2b] prepared from the acid itself and also by the decomposition of ditolylsulfonmethylamine.[3b]

[1] Ann. 142, 93 (1867).

[2] Ber. 9, 1586 (1876).

[3] Ber. 3, 965 (1870).

[4] D. R. P. 224,019; Chem. Zentr. 1910, (II), 513.

[5] Ber. 42, 3821 (1909).