124 



AROMATIC ALCOHOLS AND PHENOLS [60 P-61 A. 



benzoic acid (as under quinol [71; I]), 

 into antkranilic acid, salicylic acid, and 

 phenol as under C. 



[Q.] Hydrojuglone [90] gives phenol 

 among the products of its fusion with 

 potash (Mylius, Ber. 18, 475). 



[R.] Acetic aldehyde [92] gives phenol 

 in small quantity by the action of fuming 

 sulphuric acid and fusion of the product 

 with alkali (Berthelot, Comp. Rend. 

 128, 336). 



[S.] Pulegone [128] on heating with 

 formic acid or with water under pressure 

 gives (with acetone) methylcyclohexan- 

 one (Wallach, Ann. 289, 338; 340; 

 Klages, Ber. 32, 2567). The latter by 

 the action of phosphorus pentachloride 

 yields (as final product) tetrahydrochlor- 

 toiuene, and this by the action of 

 bromine gives m-chlortoluene (Klages, 

 Ber. 32, 2567). Subsequent steps as 

 under H and E. 



Mineral acids (especially sulphuric) 

 may also be used for converting pule- 

 gone into the cycloketone (Zelinsky, 

 Ber. 30, 1532; Wallach, Ber. 32, 



333 8 )- 



[T.] From o-coumaric acid [Vol. II], 

 which gives phenol on dry distillation. 



[TL] From malonic acid [Vol. II] and 

 ethyl alcohol [14] through dicarboxy- 

 glutaconic ester and glutaconic ester. 

 The sodium derivative of the latter on 

 heating with alcohol at 150 gives 

 hydroxyisophthalic acid (Lawrence and 

 W. H. Perkin, junr., Proc. Ch. Soc. 17, 

 47 : see also under cymene [6 ; XV]). 

 The latter gives phenol on distillation. 



NOTE : Generators of dicarboxyglutaconic 

 ester are given under cymene as above. Glu- 

 taconic acid is formed by the action of alcoholic 

 soda or hydrochloric acid on the dicarboxy- 

 glutaconic ester (Conrad and Gutzeit, Ann. 

 222, 253 ; Gutzeit and Bolam, Journ. pr. Ch. 

 [2] 54, 372). 



Also from formic and acetic acids and alcohol 

 or from malic acid through coumalic acid = 

 formylglutaconic anhydride (see under n-butyl 

 alcohol [17 ; J ; O, &c.]). Coumalic acid gives 

 glutaconic acid on heating with barium hydr- 

 oxide solution (v. Pechmann, Ann. 264, 301). 



Or citric acid can be converted into acetonedi- 

 carboxylic acid (see under n-secondary amyl 

 alcohol [21 ; H]) and this, by reduction with 

 sodium amalgam, gives #-hydroxyglutaric acid 

 (v. Pechmann and Jenisch, Ber. 24, 3250) which, 

 on distillation in a vacuum or with sulphuric 

 acid, yields glutaconic acid (Ibid. 3256). 



Or from acetic acid (ester) and acrylic acid 

 (ester) through pyrazolin-3:5-dicarboxylic ester 



by the interaction of diazoacetic and acrylic 

 esters (Buchner and Papendieck, Ann. 273, 

 232 : generators of acrylic acid are referred to 

 under benzyl alcohol [54 ; E], under resorcinol 

 [70; F], and under acetone [106 ; S]). Gluta- 

 conic ester is formed by the distillation of pyraz- 

 olindicarboxylic ester (Buchner, Ber. 23, 703). 

 a-Hydroxyglutaric acid [Vol. II] on dehydration 

 gives glutaconic acid among other products 

 (Paolini, Gazz. 32, 402). 



61. Orthocresol; 2-Methylplieuol. 

 HO 



CH 3 



NATURAL SOURCES. 



Occurs as a salt of o-cresylsulphuric 

 acid in urine of herbivorous animals and, 

 to a small extent, in human urine. 

 Found also among the products of 

 putrefaction of horse liver (Baumann, 

 Ber. 9, 1389 ; Zeit. physiol. Ch. 2, 335 ; 

 Preusse, Ibid. 355; Baumann and Brie- 

 ger, Ibid. 3, 149 ; 252 ; Brieger, Ibid. 4, 

 204 ; Baumann, Ibid. 304 ; Baumann 

 and Brieger, Ber. 12, 804; Baumann, 

 Zeit. physiol. Ch. 6, 183 ; Brieger, Ibid. 

 8, 311 : see also Salkowski, Ibid. 12, 



215)- 



The o-cresol complex exists possibly 



in bebeerine, an alkaloid found in the 

 bark of Nectandra rodioei from British 

 Guiana, in the bark and leaves of Bwxus 

 semjiervirens, and in the root of Cissam- 

 pelos pareira (see Scholtz, Ber. 29, 2054, 

 and Arch. Pharm. 236, 530; Ch. Centr. 

 1898,2,983). 



A cresol (? isomeride) has been found 

 in cascarilla oil from the bark of Croton 

 eluteria (Fendler, Arch. Pharm. 238, 

 671). 



SYNTHETICAL PROCESSES. 



[A.] From toluene (see under benzyl 

 alcohol [54 ; A and D to T]). Toluene 

 on sulphonation gives (with para-) ortho- 

 sulphonic acid (Engelhardt and Lat- 

 schinoff, Zeit. [2] 5, 61 7 ; Wolkoff, Ibid. 

 6, 321 ; Claesson and Wallin, Ber. 12, 

 1848; Noyes, Am. Ch. Journ. 8, 176), 

 and this gives o-cresol by potash fusion 

 (Engelhardt and Latschinoff, loc. cit. 

 620). 



