146 



AROMATIC ALCOHOLS AND PHENOLS [70 J-71 C. 



[J.] From quincl [7l] through hy- 

 droxyquinol by alkaline fusion (Earth 

 and Schreder, Monats. 4, 176 ; 5, 590). 

 Hydroxyquinol (or its carboxylic acid) 

 gives dihydroresorcinol on reduction 

 with sodium amalgam (Thiele and 

 Jaeger, Ber. 34, 2841). Subsequent 

 treatment as above under F. 



71. Quiiiol ; Hydroquinoiie ; 



Faradihydroxybenzeiie ; 



Fyrogentisic acid ; 



1 : 4-Flienediol. 



HO 



NATURAL SOURCES. 



Occurs to the extent of from 2 to 

 5 per cent, in the S. African ' sugar 

 bush/ Protect mettifera (Hesse, Ann. 

 290, 317), and as glucoside (arbutin) 

 in the berries of the red whortleberry, 

 Vaccinium vitis-idcea, in leaves of the 

 red bearberry, Arctostapkylos uva-ursi, 

 and A. glauca, and of Pyrola wmbellata, 

 P. rotundifolia, P. chlorantJia, P. elliptica, 

 Calluna vulgaris, Ledum palnstre, Epigtsa 

 repens, Gaultheria procumbens, and 

 Chimaphila maculata (Kawalier, Ann. 

 82, 241 ; 84, 356; Zwenger and Him- 

 melmann, Ann. 129, 203; Claassen, 

 Jahresber. 187O, 877; 1885, 1761; 

 Schiff, Ann. 206, 165; Schunck and 

 Marchlewski, Ann. 278, 354 ; Maisch, 

 Am. Journ. Pharm. 46, 319). 



Arbutin is decomposed by the moulds 

 Aspergillus niger, A. glaucus, and Peni- 

 cillium glaucum with the liberation of 

 quinol (Puriewitsch, Ber. deutsch. bot. 

 Gesell. 16, 368). 



The quinol complex is contained in 

 euxantfione [136], gentisin [137], homo- 

 gentisic acid [Vol. II], methylarlutin 

 [159], and (possibly) in saponarin, a 

 glucoside contained in Saponaria offici- 

 nalis (Barger, Ber. 35, 1296). 



Quinol occurs as a constituent of 

 normal urine (Platt, Am. Ch. Journ. 

 19, 382). 



SYNTHETICAL PROCESSES. 



[A.] From pJienol through p-iodo- 

 phenol by various iodising processes 

 (see under catechol [69 ; A]), and fusion 

 of the latter with potash at a tempera- 

 ture below 165 (Kbrner, Zeit. [2] 2, 

 662; 731; 4, 322). 



Or from phenol through p-nitrophenol 

 by nitration, p-aminophenol by reduc- 

 tion, and the diazo-reaction with the 

 latter (Weselsky and Schuler, Ber. 9, 

 1160). 



From phenol by the action of potas- 

 sium persulphate in alkaline solution 

 (Ch. Fab. vorm. E. Schering, Germ. 

 Pat. 81068 of 1894; Ber. 28, Ref. 

 666). 



Quinol is among the products of 

 electrolysis of a solution of phenol by 

 an alternating current in presence of 

 magnesium sulphate and acid carbonate 

 (Drechsel, Journ. pr. Ch. [2] 29, 249), 

 and also among the products of the 

 oxidation of phenol by hydrogen per- 

 oxide (Martinon, Bull. Soc. [2] 43, 



156). 



From phenol through p-nitrosophenol 

 = quinone-oxime (Bridge, Ann. 277, 85; 

 Wurster, Ber. 20, 2632), and the action 

 of hydroxylamine on the latter (Hepp, 

 Ber. 1O, 1654). 



From phenol and carbon tetrackloride 

 [l; L] through 5-nitrosalicylic and 

 gentisic acids as under euxanthone 

 [136 ; C]. From gentisic acid as under 

 C below. 



[B.] Qiiinone [142] gives quinol on 

 reduction (Wb'hler, Ann. 51, 152). The 

 reduction can be effected by alcohol 

 under the influence of light (Ciamician 

 and Silber, Ber. 33, 2911 ; 35, 3594). 

 Also by isopropyl alcohol and formic 

 acid under similar circumstances (Ibid. 

 34, 1542). Quinol (and p-diethoxy- 

 quinone) is formed, by heating quinone 

 with alcohol in the presence of zinc 

 chloride (Knoevenagel and Biickel, 

 Ber. 34, 3798). 



[C.] Salicylic acid [Vol. II] can by 

 various processes be iodised or bromi- 

 nated so as to form 5-iodo- or 5-brom- 

 salicylic acid (Gerhardt, Ann. Chim. [3] 

 7, 217; Cahours, Ibid. 1O, 341; 13, 

 99; Henry, Ber. 2, 275; Lautemann, 



