86 H-87 B.] 



[H.] Benzene [6] can, by processes 

 other than those comprised under B, C, 

 and D, be converted into phloroglu- 

 cinol : 



i .-3 : 5-Benzenetrisulphonic acid (Sen- 

 hofer, Ann. 174, 243 ; Jackson and 

 Wing-, Am. Ch. Journ. 9, 329) gives 

 phloroglucinol when fused with caustic 

 soda (Earth and Schreder, Ber. 12, 



4I7)- 



Or benzene can be converted into 



nitrobenzene and aniline, the latter 

 into 2:4: 6-tribromaniline by bromina- 

 tion (Fritzsche, Ann. 44, 291 ; Hof- 

 mann, Ann. 53, 50 ; Silberstein, Journ. 

 pr. Ch. [2] 27, 101), the NH 2 -group 

 replaced by hydrogen by the diazo- 

 method (Meyer and Stiiber, Ann. 165, 

 173"; Baessmann, Ann. 191, 206; 

 Jackson and Moore, Am. Ch. Journ. 

 12, 167; 14, 335). The I :3:5-tri- 

 brombenzene thus formed can be con- 

 verted into 3 : 5-dibromphenol and 

 phloroglucinol as under A. 



Or from aniline through sulphanilic 

 acid and benzenediazosulphonic acid, 

 the latter giving picric acid by the 

 action of nitric acid (Wenghb'fer, Germ. 

 Pat. 125096 of 1900; Ch. Centr. 1901, 

 2, 1105). 



Or benzene can be converted into 

 1:3: 5-trinitrobenzene by extreme nitra- 

 tion (Hepp, Ann. 215, 345), the latter 

 reduced to the corresponding triamine, 

 and then converted into phloroglucinol 

 as under B. 



Or toluene on nitration gives 2:4:6- 

 trinitrotoluene (Wilbrand, Ann. 128, 

 178), and this on oxidation with nitric 

 acid yields 2:4: 6-trinitrobenzoic acid 

 (Tiemann and Judson, Ber. 3, 224). 

 The 2:4: 6-triaminobenzoic acid gives 

 phloroglucinol on heating with water 

 (Cassella & Co., Germ. Pat. 102358 

 of 1897; Ch. Centr. 1899, 1, 1263). 



NOTE : Generators of toluene (see under 

 benzyl alcohol [54 ; A ; &c.]) thus become 

 generators of phloroglucinol. 



[I.] Furfural [126] on oxidation with 

 silver oxide or alkaline permanganate, 

 or on treatment with alcoholic potash, 

 gives pyromucic acid (Schwanert, Ann. 

 114, 63 ; 116, 257 ; Ulrich, Jahresber. 

 1860, 269; Beilstein and Schmelz, 



PHLOROGLUCINOL 



163 



Ann. Suppl. 3, 275; Limpricht, Ann. 

 165, 279; Bieler and Tollens, Ann. 

 258, 120; Schiff, Ann. 239, 374; 

 261, 255). This acid, by the action of 

 bromine in water, yields mucobromic 

 acid (Beilstein and Schmelz, loc. cit. 

 276 ; Jackson and Hill, Am. Ch. Journ. 

 3, 105), and this, by the action of 

 nitrites, gives nitromalonic aldehyde 

 (Hill and Sanger, Ber. 15, 1906; Hill 

 and Torrey, Ber. 28, 2597 ^ Am. Ch. 

 Journ. 22, 89). The latter, on decom- 

 position by aqueous hydrochloric acid, 

 yields (with formic acid) 1:3: 5-trinitro- 

 benzene (Ibid.), which can be converted 

 into phloroglucinol as above under B. 



[J.] Iretol [88] is reduced to phloro- 

 glucinol by sodium amalgam (Tiemann 

 and G. de Laire, Ber. 26, 2026). 



87. Antiarol; 



l-Hydroxy-3 :4; 5-trimethoxybenzene; 



1:3:4: 5-Phenetetrol 3:4: 5-Tri- 



methyl Ether. 



HO 



OCH 3 

 6CH 3 



NATURAL SOURCE. 



The sap of the upas tree, Antiaris 

 toxicaria (Kiliani, Arch. Pharm. 234, 



438). 



SYNTHETICAL PROCESSES. 



[A.] From pyrogallol [84] through 

 the trimethyl ether by methylation, 

 3 : 5-dimethoxyquinone by oxidation 

 with nitric acid, 3 : 5-dimethoxyquinol 

 by reduction, and methylation of the 

 latter by the usual method (Will, Ber. 

 21, 61 2; 2020). 



[B.] From catecliol [69] through 

 guaiacol. The latter, on sulphonation 

 at a low temperature, gives a consecu- 

 tive monosulphonic acid which yields 

 pyrogallol methyl ether on fusion with 

 alkali (Hoffmann, La Roche & Co., 



M 2 



