156 



AROMATIC ALCOHOLS AND PHENOLS [76 A-78. 



this synthesis are also obtainable from 

 2 : 4-dinitrotoluene by partial reduction 

 (Beilstein and Kuhlberg, Ann. 155, 14 ; 

 Graeff, Ann. 229, 343 ; Anschiitz and 

 Heusler, Ber. 19, 2161); or the 2:4- 

 toluylenediamine may be monacetylated, 

 converted into 4-acetamino-2-cresol by 

 the diazo-method, hydrolysed, and the 

 4-amino-2-cresol converted into cresor- 

 cinol as before (Wallach, Ber. 15, 2832 

 and 2835). 



[B.] From resorcinol [70] and carbon 

 disulp/iide [16O]. A mixture of these 

 compounds on heating in presence of 

 potassium sulphide solution gives resor- 

 cinoldithiocarbonic acid. The latter on 

 reduction with zinc dust and acetic 

 acid gives cresorcinol (Schall, Journ. pr. 

 Ch. [2] 54, 415)- 



77. /3-Orcinol ; 

 3 : 5-Dihydroxy-p-xyleiie ; 



p-Xylorcin ; 

 1 : 4-Dimethyl-3 : 5-Pheiiecliol. 



HO 



NATURAL SOURCES. 



The y8-orcinol complex is contained 

 in /3-erythrin from the lichen Eoccella 

 fuciformis, in barbatic acid from the 

 lichen Usnea barbata, and in /3-usnic 

 or cladonic acid from the lichen Cla- 

 donia rangiferina. (For occurrence of 

 /3-erythrin, which yields /3-orcinol 

 through picroerythrin, see under orcinol 

 [75] ; for barbatic acid, Stenhouse and 

 Groves, Ann. 203, 302 ; for /3-usnic = 

 cladonic acid, Stenhouse, Ann. 68, 98 ; 

 155, 58 j Hesse, Ann. 117, 346 : cla- 

 donic acid may be a mixture of usnic 

 and barbatic acids, Paterno, Gazz. 6, 

 113 ; 12, 231 ; Stenhouse, lac. cif. 285 : 

 for barbatic acid in various species of 

 Usnea see Hesse, Ber. 30, 357 : accord- 

 ing to the latter author cladonic acid is 

 a mixture of usnic and atronoric acids : 

 for barbatic acid in Usnea longissima 

 see Zopf, Ann. 297, 293 ; Hesse, Journ. 

 pr. Ch. [2] 57, 239 ; in Alectoria oc/tro- 



leuca, Zopf, Ann. 306, 298 ; in Usnea 

 barbata fi-hirta, Hesse, loc. cif. 65, 537 ; 

 in Usnea ceratina and U. clasypoga (?), 

 Zopf, Ann. 324, 39). 



Atranorin = atranoric acid, which is 

 contained in a large number of lichens 

 (for occurrence see under methyl alcohol 

 [13]) ; and ceratophyllin = atraric acid 

 = physcianin, which is a decomposi- 

 tion product of atranorin, also contain 

 the /3-orcinol complex (Hesse, Ber. 3O, 

 1988). 



The complex is contained in rhizonic 

 and rhizoninic acids from llhizocarpon 

 geographicum, var. contiguum (Ibid. 31, 

 664 ; Journ. pr. Ch. [2] 58, 527). 



Coccellic acid from Cladonia coccifera, 

 C. amauracrtea, and C. floerkeana = C. 

 bacillaris, contains the rhizoninic and 

 therefore the /3-orcinol complex (Ibid. 

 Ann. 284, 107; Journ. pr. Ch. [2] 57, 

 274 ; 58, 472 ; 62, 447 '> Z P^ Ann - 

 300, 330). 



SYNTHETICAL PROCESS. 



[A.] From toluene [54 ; A, &c.] and 

 p-xylene (see under metacresol [62 ; A]). 

 The xylene on nitration gives (with 

 other isomerides) 3 : 5-dinitro-p-xylene, 

 which by reduction with nascent am- 

 monium sulphide yields 5-nitro-3-amino- 

 p-xylene = m-nitro-p-xylidine (Fittig, 

 Ahrens, and Mattheides, Ann. 147, 22). 

 The latter by the diazo-method gives 

 5-nitro-p-xylenol-3 (Kostanecki, Ber. 

 19, 2320), the corresponding amino- 

 xylenol by reduction with tin and 

 hydrochloric acid, and /3-orcinol by the 

 diazo-method (Ibid. 2321). 



78. Mesorcinol; 

 1:3: 5-Trimethyl-2 ; G-Phenediol. 



CH, 



OH 



NATURAL SOURCE. 



Coccellic acid from the lichens Cla- 

 donia coccifera, &c. (see under /3-orcinol 

 [77]), hydrolyses to rhizonic and coccel- 



