126 



AROMATIC ALCOHOLS AND PHENOLS 



[61 A-B. 



1 88; Ber. 11, 18), the amide of which 

 gives on oxidation with chromic acid or 

 potassium permanganate 6-sulphamide- 

 m-toluic acid (Remsen and lies, Am. 

 Ch. Journ. 1, 41 ; Jacobsen, Ber. 11, 

 895 ; Coale and Remsen, Am. Ch. 

 Journ. 3, 205). The latter on potash 

 fusion yields 6-hydroxy-m-toluic acid 

 (Jacobsen, loc. cit. 897; Remsen and 

 lies, loc. cit. 48 ; 1 14 ; Ber. 11, 462 ; 

 Mahon, Am. Ch. Journ. 4, 186), which 

 on heating with hydrochloric acid at 

 180-185 gives o-cresol. 



Or m-xylene can be nitrated, the 6- 

 nitro-m-xylene oxidised to 6-nitro-m- 

 toluic acid by chromic acid (Beilstein 

 and Kreusler, Ann. 144, 168), reduced 

 to the amino-acid (Ibid. 177), the latter 

 converted into the 6-hydroxy-m-toluic 

 acid by the diazo-reaction (Remsen and 

 Kuhara, Am. Ch. Journ. 3, 428), and 

 the hydroxy-acid converted into o-cresol 

 as above. 



Or m-xylene may be brominated, the 

 product oxidised to 6-brom-m-toluic acid 

 by chromic acid (Fittig, Ahrens, and 

 Mattheides, Ann. 147, 32 ; Jacobsen, 

 Ber. 14, 2352), the 6-hydroxy-acid 

 formed by potash fusion of the bromo- 

 acid (Jacobsen, loc. cit.}, and then con- 

 verted into o-cresol as before. 



When m-xylene is sulphonated the 

 2-sulphonic acid is produced as well as 

 the 4-sul phonic acid (Jacobsen, Ann. 

 184, 188; Ber. 10, 1015; 11, 19), and 

 the amide of the former on oxidation 

 with chromic acid gives 2-sulphamide- 

 m-toluic acid (Ibid. Ber. 11, 901), which 

 on fusion with potash yields 2-hydroxy- 

 m-toluic (/3-cresotic = o-homosalicylic) 

 acid. The latter on heating with strong 

 hydrochloric acid is converted into o- 

 cresol. 



Or m-xylene can be directly oxidised 

 to m-toluic acid by dilute nitric acid 

 (TawildarofF, Zeit. [2] 6, 419; Ber. 4, 

 410 ; Bruckner, Ber. 9, 406 ; Reuter, 

 Ber. 17, 2028). m-Toluic acid on 

 nitration gives (with much 4-nitro-acid) 

 a small quantity of 2-nitro-m-toluic 

 acid (Jacobsen, Ber. 14, 2353 ', Van 

 Scherpenzeel, Rec. Tr. Ch. 20, 149), 

 and this on reduction to the amino-acid 

 and application of the diazo-reaction 

 yields 2-hydroxy-m-toluic acid (Jacobsen, 



loc. cit.}, which can be converted into 

 o-cresol as before. 



Or m-toluic acid may be brominated 

 with the formation of 4-brom- and 

 6-brom-m-toluic acid (Jacobsen, loc. 

 cit.}, the latter being convertible into 

 6-hydroxy-m-toluic acid by potash 

 fusion and then into o-cresol as above. 



NOTE : All the generators of toluene referred 

 to under benzyl alcohol (54 ; A and D to T, 

 &c.) by the foregoing methods become generators 

 of o-cresol. 



[B.] From acetone [106] through 

 mesitylene (see under benzyl alcohol; 

 [54; D]), mesitylenic acid by oxida- 

 tion with dilute nitric acid (Fittig, 

 Ann. 141, 144; Fittig and Bruckner, 

 Zeit. [2] 4, 493; Ann. 147, 45); 

 m-xylene by distilling mesitylenic acid 

 with lime (Fittig and Velguth, Ann. 

 148, 10), and then as under the fore- 

 going methods. Or from acetone 

 through phorone (2 : 6-dimethyl-2 : 5- 

 heptadienone-4) by the action of lime 

 or acids (Fittig, Ann. 110, 32 ; Baeyer, 

 Ann. 14O, 301), pseudocumene (1:2:4- 

 trimethylbenzene) by the action of phos- 

 phorus pentoxide or zinc chloride on 

 phorone (Jacobsen, Ber. 10, 855), xylic 

 acid (i : 3-dimethyl-4-benzoic acid) by 

 the oxidation of pseudocumene by dilute 

 nitric acid (Fittig and Laubinger, Ann. 

 151, 269), m-xylene by distilling xylic 

 acid with lime (Fittig and Bieber, Ann. 

 156, 236), and then as above. Or from 

 acetone through triacetonamine by the 

 action of ammonia (Heintz, Ann. 178, 

 305; 189, 214), nitrosotriacetonamine 

 by the action of nitrous acid (Ibid. 185, 

 I ; 187, 233), phorone by the action of 

 caustic alkali on the nitrosamine (Ibid. 

 187, 250), and then as above. 



NOTE : Mesitylenic acid is formed also in 

 small quantity by passing carbon monoxide over 

 a mixture of sodium ethylate and sodium acetate 

 heated to 205, or by heating this same mixture 

 with zinc dust (Geuther and Frohlich, Ann. 

 202, 310). Also under similar conditions from 

 sodium isovalerate and ethylate at 160 (Loos, Ibid. 



Mesitylene also is converted by further 

 oxidation into uvitic acid (see under 

 benzyl alcohol [54; D]), and this on 

 heating the calcium salt with a small 

 quantity of lime gives m-toluic acid 

 (Bb'ttinger and Ramsay, Ann. 168, 255), 



