154 



AROMATIC ALCOHOLS AND PHENOLS 



[75 A r C. 



Or toluene may be nitrated, the o- 

 nitrotoluene reduced to o-toluidine, the 

 latter sulphonated (Gerver, Ann. 169, 

 374 ; Pagel, Ann. 176, 392 ; Nevile 

 and Winther, Trans. Ch. Soc. 37, 

 626; Ber. 13, 1941), the 2-toluidine- 

 5-sulphonic acid brominated, and thus 

 converted into 3-brom-2-toluidine-5- 

 sulphonic acid (N. and W. Ber. 13, 

 1942). The latter on replacing the 

 NH 2 -group by hydrogen by the diazo- 

 method gives 3-bromtoluene-5-sulphonic 

 acid (Ibid. 1944), from which orcinol 

 can be obtained by potash fusion (Ibid. 

 Ber. 15, 2990). 



Or 2-toluidine-5-sulphonic acid may 

 be converted into 2-toluidine-3 : 5-di- 

 sulphonic acid by further sulphonation 

 (Ibid. 2992 ; Hasse, Ann. 230, 288), 

 the disulphonic acid into toluene-3 : 5- 

 disulphonic acid by replacing the 

 NH 2 -group by hydrogen (Limpricht and 

 Hasse, Ber. 18, 2177; Ann. 23O, 295; 

 Nevile and Winther, Ber. 15, 2992), 

 and the disulphonic acid into orcinol by 

 potash fusion (N. and W. loc. cit. 2993). 



Or o-toluidine may be converted into 

 3 : 5-dibrom-2-toluidine by bromination 

 (Wroblewski, Ann. 168, 162), into 

 3 : 5-dibromtoluene by replacing the 

 NH 2 -group by hydrogen (N. and W. 

 Ber. 13, 966), and the dibromtoluene 

 into orcinol by potash fusion (Ibid. 15, 

 3992). 



Toluene may also be nitrated, the 

 p-nitrotoluene reduced, the p-toluidine 

 converted into 3 : 5-dibrom-4-toluidine 

 by bromination (Wroblewski, Ann. 

 168, 1 88), the NH 2 -group replaced by 

 hydrogen (Ibid.), and the 3 : 5-dibrom- 

 toluene converted into orcinol as above. 



Or p-toluidine may be converted into 

 3 : 5-dinitro-4-toluidine by nitration and 

 hydrolysis of the acetyl- or benzoyl- 

 derivative (Beilstein and Kuhlberg, Ann. 

 158,341; Hiibner, Ann. 208,312; 222, 

 74), the NH 2 -group replaced by hydro- 

 gen (Stadel, Ber. 14, 901 ; Ann. 217, 

 189; Hiibner, Ann. 222, 74; Nevile 

 and Winther, Ber. 15, 2984 ; Hb'nig, 

 Ber. 20, 2418), the 3 : 5-dinitrotoluene 

 reduced by ammonium sulphide to 5- 

 nitro-3-toluidine (Stadel, Ann. 217, 189; 

 N. and W. loc. cit. 2985), and the latter 

 converted into 5-nitro-3-cresol by the 



diazo-method (N. and W. loc. cit. 2986). 

 The nitrocresol on reduction and re- 

 placement of the NH 2 -group byhydroxyl 

 by the diazo-method gives orcinol (Ibid. 

 2987). 



p-Acettoluide may also be brominated 

 and then nitrated, or nitrated and then 

 brominated so as to give on hydrolysis 

 3-brom-5-nitro-4-toluidine (Wroblew- 

 ski, Ann. 192, 202 ; N. and W. Ber. 13, 

 968). The latter on replacement of the 

 NH 2 -group by hydrogen gives 3-brom- 

 5-nitrotoluene, and by reduction 5- 

 brom-3-toluidine, from which, by the 

 diazo-method, 5-brom-3-cresol can be 

 obtained, and this also gives orcinol on 

 fusion with potash (N. and W. Ber. 

 15, 2991 : see also Nevile, Eng. Pat. 

 4389 of 1881). 



[B.] Paracresol [63] when the ethyl 

 ether is nitrated is converted into the 

 3 : 5-dinitro-p-cresol ether (Stadel, Ann. 

 217, 161). Or p-cresol may be nitrated 

 (Frische, Ann. 224, 139 : see also Arm- 

 strong and Field, Ber. 6, 974), and 

 converted into the dinitro-ether by the 

 action of ethyl iodide on the silver salt 

 (Noelting and Salis, Ber. 15, 1859). 

 The dinitro-ether on treatment with 

 alcoholic ammonia is converted into 

 3 : 5-dinitro-4~toluidine (Stadel, loc. cit. 

 1 86), from which 3 : 5-dinitrotoluene, 

 5-nitro-3-toluidine, 5-nitro-3-cresol, 5- 

 amino-3-cresol and orcinol can be 

 obtained as under A. 



[C.] Citric acid [Vol. II] when heated 

 with sulphuric acid gives acetonedi- 

 carboxylic (/3-ketoglutai'ic or 3-penta- 

 nonedicarboxylic) acid (v. Pechmann, 

 Ber. 17, 2543; 18, 2289; 19, 1446, 

 2465 ; 2694 ; 20, 145 ; 24, 857 ; 3250; 

 4095 ; Ann. 261, 151 ; v. P. and Neger, 

 Ann. 273, 1 86; Henry and v. P. Ber. 

 26, 997 ; also Germ. Pat. 32245 of 

 1884). The diethyl ester of this acid 

 by the action of sodium gives dihydr- 

 oxyphenyltricarboxylic triethyl ester 

 (Cornelius and v. P. Ber. 19, 1448 ; 

 v. P. and Wolman, Ber. 31, 2014), and 

 the latter on hydrolysis by alcoholic 

 potash gives s-dihydroxyphenylacetic 

 (3 : 5-phenediolethylic) acid (C. and v. P. 

 loc. cit. 1449), the silver salt of which 

 yields orcinol on dry distillation (Ibid. 

 H50- 



