236 



AROMATIC ALDEHYDES AND KETONES [144 C. 



144. Metahydroxyantliraquhioiie ; 

 2-Hydroxyanthraquinone. 



CO, 



OH 



NATURAL SOURCE. 



In Chay root (Oldenlandia umbellata) 

 from N. Burma, Ceylon, Madras 

 Presidency, Malabar and Coromandel 

 coasts (A. G. Perkin and Hummel, 

 Trans. Ch. Soc. 63, 1177). 



SYNTHETICAL PROCESSES. 



[A.] From phenol [60] and phthalic 

 anhydride (see under benzyl alcohol 

 [54; B,]). A mixture of these gives 

 (with i-hydroxy-) 2-hydroxyanthra- 

 quinone on heating 1 with strong" sul- 

 phuric acid (Caro and Baeyer, Ber. 7, 

 969). 



[B.] From benzole acid [Vol. II] 

 through m-nitro-, m-amino-, and m-hy- 

 droxybenzoic acid (see under phenol [6O ; 

 E]). The latter, when heated with 

 benzoic acid and strong- sulphuric acid 

 at 300, gives m-hydroxyanthraquinone 

 (Liebermann and Kostanecki, Ann. 240, 

 263). 



[C.] Anthracene and anthraguinone can 

 be synthesised by various processes : 



Syntheses of Anthracene. 



From toluene through benzyl chloride 

 (see under benzyl alcohol [54; A]). 

 The latter gives anthracene on heating 

 with water at 180 (Limpricht, Ann. 

 139, 308 ; Zincke, Ber. 7, 278), or by 

 the action of aluminium chloride (W. 

 H. Perkin, junr., and Hodgkinson, Trans. 

 Ch. Soc. 37, 726; Schramm, Ber. 26, 

 1706). 



Or benzyl chloride and ethyl alcohol 

 give benzyl ethyl ether (Cannizzaro, 

 Jahresber. 1856, 581), which on heating 

 with phosphorus pentoxide gives (with 

 ethylene) anthracene (Henzold, Journ. 

 pr. Ch. [2] 27, 518). 



Benzyl trichloracetate (from benzyl 



chloride and trichloracetic acid} interacts 

 with benzene, in presence of aluminium 

 chloride, to form a compound which 

 gives anthracene on distillation (Delacre, 

 Bull. Soc. [3] 13, 302). 



Dihydroanthracene (furnishing an- 

 thracene by oxidation) is probably 

 among the products of the oxidation of 

 toluene by manganese dioxide and sul- 

 phuric acid (Weiler, Ber. 33, 464). 



Or from toluene through the o-bromo- 

 derivative and o-brombenzyl bromide 

 (Jackson, Ber. 9, 932), and the action of 

 sodium on the latter in ethereal solution 

 (Jackson and White, Am. Ch. Journ. 2, 

 391; Ber. 12, 1965). 



From benzene and acetylene dibromicle 

 (or tetrabromide) by treating a mixture 

 with aluminium chloride or bromide 

 (Anschiitz, Ann. 235, 156; 165; An- 

 schiitz and Eltzbacher, Ber. 16, 623). 



Or from benzene and methylene chloride 

 [55; E, p. 117] by the action of 

 aluminium chloride (Friedel, Crafts, and 

 Vincent, Ann. Chim. [6] 11, 264 ; Bull. 

 Soc. [2] 40, 97 ; 41, 325). Hexa- and 

 pentachlorethane and perchlorethylene, 

 trich lore thane, and dichlorethyl ether all 

 give anthracene when condensed with 

 benzene by means of aluminium chloride 

 (Mouneyrat, Bull. Soc. [3] 19, 554; 

 557 ; Gardeur, Bull. Acad. Roy. Belg. 

 [3] 34, 920). 



Naphthalene [12] can be converted 

 into o-toluic acid (benzyl alcohol [54; 

 B]), and this, when heated in brom- 

 ine vapour at 140, gives phthalide, 

 rn 



C 6 H 4<CH ^* Tnelatter ; n(iistil]ation 

 with lime, yields anthracene (Krczmar, 

 Monats. 19, 456). 



NOTE : Toluenethusalso becomes a generator 

 of anthracene through o-toluic acid (see under 

 m-cresol [62 ; A]). 



Phenol [60] and benzyl chloride (or 

 benzyl alcohol [54]) condense to form 

 p-benzylphenol under the influence of 

 zinc chloride or other condensing agents 

 (Paterno, Gazz. 2, 2; 3, 121; Paternb 

 and Fileti, Ibid. 5, 382 ; Liebmann, 

 Ber. 14, 1844; W. H. Perkin, junr., 

 and Hodgkinson, Trans. Ch. Soc. 37, 

 723). p-Benzylphenol gives anthracene 

 among other products on distillation 



