150 



AROMATIC ALCOHOLS AND PHENOLS [71 R-X. 



Also amino- and diamino-p-xylene give xylo- 

 quinone on oxidation (Carstanjen, Journ. pr. 

 Ch. [2] 23, 423 ; Noelting, Witt, and Forel, Ber. 

 18, 2667 ; Nietzki, Ann. 215, 168). Generators 

 of the xylenes (see under o-cresol [61 ; A and B] 

 and p-cresol [63 ; A and B]) thus become 

 generators of dihydroxyterephthalic acid and 

 quinol. 



[S.] From oxalic and acetic acids 

 [Vol. II] and alcohol [14] through 

 ketipic acid (diacetyldicarboxylic or 

 3 : 4-hexadionediacid) by the action of 

 ethylchloracetate on oxalic diethyl ester 

 in the presence of zinc, and hydrolysis 

 of the ketipic ester formed (Fittig, 

 Daimler, and Keller, Ann. 249, 183). 

 Ketipic acid on dry distillation or on 

 heating with dilute sulphuric acid gives 

 diacetyl (Ibid. 200), which can be con- 

 verted into p-xyloquinone, &c., as under 

 N and Q. 



Ketipic acid can also be obtained from 

 oxalic and acetic esters in ethereal solu- 

 tion by the action of dry sodium ethylate 

 (Wislicenus, Ber. 2O, 589 ; Ann. 246, 

 328). 



[T.] Benzene [6], irrespective of the 

 compounds of which it is the generator 

 under the preceding headings (phenol 

 [A], quinone [B], &c.), can be made to 

 lurnish quinol directly by electrolysing 

 a solution of the hydrocarbon in alcohol 

 in presence of sulphuric acid (Gatter- 

 mann and Friedrichs, Ber. 27, 1942). 

 Or by electrolysis in suspension in 

 sulphuric acid (Kempf, Germ. Pat. 

 117351 of 1899; Ch. Centr. 1901, 1, 



348). . 



Quinol is among the products of the 

 oxidation of benzene by hydrogen per- 

 oxide in presence of ferrous sulphate 

 (Cross, Bevan, and Heiberg, Ber. 33, 

 2018). 



Nitrobenzene in strong sulphuric acid 

 solution gives p-aminophenol on electro- 

 lysis (Gattermann and Koppert, Ber. 

 26, 2810; Noyes and Clement, Ibid. 

 990 ; Gattermann, Ibid. 1 844 ; 27, 

 1927), and this can be converted as 

 under A. 



Or benzene might be converted into 

 nitrobenzene, aniline, acetanilide, p- 

 nitraniline, and p-phenylenediamine. 

 The latter on heating with acids to 

 a high temperature gives quinol (Meyer, 

 Ber. 30, 2569). Aniline yields quinol 



(16-18 per cent.) on oxidation with 

 chromic acid mixture (Nietzki, Ber. 1O, 



1934)- 



Nitrobenzene on mild reduction gives 

 phenylhydroxylamine (Bamberger, Ber. 

 27, 1347; 1548; Wohl, Ibid. 1432), 

 and this on electrolysis in alcoholic 

 sulphuric acid solution (Haber, Zeit. 

 Elektroch. 4, 506), or by heating with 

 the same solution (Bamberger, Ber. 27, 

 1349 ; Bamberger and Lagutt, Ber. 

 31, 1 500), yields, among other products, 

 p-aminophenol, which can be converted 

 into quinol as under A. 



Aniline gives, among other products, 

 p-aminophenol on oxidation with hydro- 

 gen peroxide (Prudhomme, Bull. Soc. 

 [3] 1> 621), or with hypochlorous acid 

 (Bamberger and Tschirner, Ber. 31, 

 1522). 



Or phenylhydroxylamine can be oxi- 

 dised to nitrosobenzene, and this gives 

 p-aminophenol among the products of 

 the action of hot aqueous alkali (see 

 under catechol [69 ; M]). 



Aniline on methylation gives di- 

 methylaniline, which by the action of 

 nitrous acid yields the p-nitroso-deriva- 

 tive. The latter on decomposition by 

 alkali gives (with dimethylamine) p- 

 nitrosophenol (Baeyer and Caro, Ber. 7, 

 809 ; 967), which can be treated as 

 under A. p-Nitrosophenol is among 

 the products of the action of aqueous 

 alkali at ordinary temperatures on 

 nitrosobenzene (Bamberger, Ber. 33, 



1954). 



[U.] From furfural [126] and acetone 

 [106] through p-nitrophenol (see under 

 resorcinol [70; H]), and then as under 

 A above. 



[V.] From Ifevulose [155] or mannose 

 [156] through Isevulic acid (see under 

 erythritol [5O; H; I]), and then through 

 diacetyl as above under O. 



[W.] From isofiexoic acid [Vol. II] 

 through laevulic acid [5O ; E], and 

 then as above through diacetyl. 



[X.] From ma Ionic or acetic acid 

 [Vol. II] and cjlycerol [48] through 

 laevulic acid [50 ; F ; G]. Or from 

 glycerol through glyceric acid and 

 pyroracemic acid (see under benzyl 

 alcohol [54; F]), and then as below 

 under BB. 



