APPENDIX 



291 



144. Metahydroxyaiithraquinone 

 (p. 236). 



Syntheses of Anthracene. 



Nascent acetylene acts on benzene in 

 presence of aluminium chloride with 

 the formation of anthracene among 

 other products (Parone, Journ. Ch. 

 Soc. 86, I, 26 ; from L'Orosi, 25, 

 148). 



To be added to synthetical pro- 

 cesses : 



[C, p. 238.] Anthraquinone is oxi- 

 dised by ammonium persulphate in sul- 

 phuric acid solution with the formation 

 of m-hydroxyanthraquinone (Wacker, 

 Journ. pr. Ch. [2] 54, 89). 



145. Alizarin (p. 238). 



To be added to synthetical pro- 

 cesses : 



[A, p. 238.] For synthesis of alizarin 

 from catechol and phthalic anhydride 

 see further Liebermann and Hohenem- 

 ser, Ber. 35, 1779). 



[B, p. 239.] Anthraquinonesulphonic 

 acid on extreme reduction by hydriodic 

 acid and phosphorus or by sodium 

 amalgam or ammonia and zinc dust 

 gives 2-anthracenesulphonic acid (Lie- 

 bermann, Ann. 212, 48 ; 57 ; Bischof 

 and Liebermann, Ber. 13, 47 ; 15, 852 : 

 according to Heffter, Ber. 28, 2262, 

 this sulphonic acid is also formed by 

 the direct sulphonation of anthracene 

 by dilute sulphuric acid). By alkaline 

 fusion this sulphonic acid yields 2- 

 anthrol (Liebermann, Ann. 212, 49). 

 By the action of sodium nitrite and 

 zinc chloride in alcoholic solution the 

 latter forms a nitroso-derivative, which 

 reduces to an amino-derivative. The 

 latter is oxidised by chromic and sul- 

 phuric acids to i : 2-anthraquinone, and 

 this is reduced by zinc dust and acetic 

 acid to i : 2-anthraquinol. The anthra- 

 quinol diacetate is oxidised by chromic 

 acid in acetic acid solution to alizarin 

 diacetate, and this yields alizarin on 

 hydrolysis (Lagodzinski, Ber. 27, 1438; 

 28, 116; 1422; 1427; 1533; 30, 

 4020). 



Anthraquinone is directly oxidised to 



alizarin by ammonium persulphate in 

 sulphuric acid solution (Wacker, Journ. 

 pr. Ch. [2] 54, 90). 



148. Aiitliragallol (p. 240). 



To be added to synthetical pro- 

 cesses : 



[D, p. 240.] From m-hydroxyanthra- 

 quinone [144] through the 1 : 3-dinitro- 

 derivative by nitration (Simon, Ber. 

 14, 464). The latter, on reduction in 

 strongly alkaline solution, or by heat- 

 ing the corresponding i : 3-diamino- 

 derivative with aqueous hydrochloric 

 acid under pressure, or by the diazo- 

 method from the diamino-compound, 

 yields anthragallol (Ibid. Germ. Pat. 

 119755 of 1898; Ch. Centr. 1901,1, 



979)- 



149. Purpurin (p. 240). 



To be added to synthetical pro- 

 cesses : 



[A, p. 24 1 .] Or quinizarin on bromina- 

 tion yields a 2-bromo-derivative (Lie- 

 bermann and Riiber, Ber. 33, 1658; 

 Farb. vorm. F. Bayer & Co., Germ. 

 Pat. 114199 of 1899; Ch. Centr. 1900, 

 2, 884). The latter, or the correspond- 

 ing chlorquinizarin, gives purpurin on 

 alkaline fusion (B. & Co., loc. cit.}. 

 Quinizarin also gives purpurin on heat- 

 ing with sulphuric and nitrous acids in 

 presence of boric acid (Ibid, as below 

 under P). 



[C, p. 241.] Alizarin gives purpurin 

 also on oxidation by ammonium per- 

 sulphate in sulphuric acid solution 

 (Wacker, Journ. pr. Ch. [2] 54, 90). 



[P, p. 241.] From m-hydroxyanthra- 

 quinone [144], which, on treatment 

 with nitrous acid in the presence of 

 strong sulphuric and boric acids, yields 

 quinizarin (Farb. vorm. F. Bayer & Co., 

 Germ. Pat. 81245 of l8 93; Ber - 28 > 

 Ref. 703; 86630 of 1895; Ber. 29, 

 Ref. 470). From quinizarin as under 

 A, p. 241, and above in this appendix. 



NOTE : Anthraquinone gives first quinizarin 

 and then purpurin on heating with sulphuric 

 acid in presence of boric acid (B. & Co, 

 Germ. Pat. 81960 of 1893 ; Ber. 28, Ref. 806). 



U 2 



