61 A.] 



ORTHOCRESOL 



125 



Toluene on nitration gives a mixture 

 of p- and o-nitrotoluenes (Glenard and 

 Boudault, Comp. Rend. 19, 505 ; Hof- 

 mann and Muspratt, Ann. 53, 221 ; 

 Kekule, Zeit. [2] 3, 225 ; Rosenstiehl, 

 Ann. Chim. [4] 27, 433 ; Reverdin and 

 La Harpe, Bull. Soc. 50, 44 : for direct 

 production of o- and p-toluidine from 

 toluene and hydroxylamine in presence 

 of aluminium chloride see Graebe, Ber. 

 34, 1778). The latter can be reduced 

 to o-toluidine, and this by the diazo- 

 reaction gives o-cresol (Kekule*, Ber. 7, 

 1006). 



Or o-nitrotoluene gives o-cresol di- 

 rectly among the products of pyrogenic 

 (electric) decomposition when mixed with 

 steam and heated to 500-1000 (Lob, 

 Zeit. Elektroch. 8, 775). 



Or p-nitrotoluene can be reduced to 

 p-toluidine, the latter converted into 

 3 -brom -p-toluidine (Wroblewski, Ann. 

 168, 153), into 3-brom-p-toluic nitrile 

 by the diazo-method (Glaus and Kunath, 

 Journ. pr. Ch. [2] 39, 486), the acid by 

 hydrolysis, 3-brom-6-nitro-p-toluic acid 

 by nitration (Glaus and Herbabny, Ann. 

 265, 364), and then through 6-nitro~3- 

 amino-p-toluic acid, 6-nitro-m-toluidine, 

 o-nitrotoluene, and o-toluidine to o-cresol 

 as above and under C and P. 



Toluene can be converted into para- 

 toluic acid by several processes : By 

 heating p-bromtoluene with sodium in 

 an atmosphere of carbon dioxide (Kekule, 

 Ann. 137, 184), or by treatment with 

 sodium and ethyl chlorocarbonate and 

 hydrolysing the ester (Wurtz, Comp. 

 Rend. 68, 1298; Ann. Supp. 7, 126). 



By the action of aluminium chloride 

 on a solution of phosgene in toluene 

 and decomposition of the chloride with 

 water (Ador and Crafts, Ber. 10, 2176). 



By nitration, reduction of p-nitro- 

 toluene to p-toluidine, the formation of 

 the nitrile by the diazo- (Sandmeyer) 

 reaction and hydrolysis (Herb, Ann. 

 258, 9 ; Glock, Ber. 21, 2650 ; Van 

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



By the action of aluminium chloride 

 on a mixture of toluene and chlorocar- 

 bamide(urea chloride) dissolved in carbon 

 disulphide, and hydrolysis of the p-toluic 

 amide thus formed (Gattermann and 

 Schmidt, Ann. 244, 51). 



By heating toluene with zinc chloride, 

 acetic acid, and phosphorus oxychloride, 

 and treating the product with dilute 

 sodium hydroxide solution (Frey and 

 Horowitz, Journ. pr. Ch. [2] 43, 116). 



By the action of aluminium chloride 

 on a mixture of toluene and phthalic 

 anhydride (see under benzyl alcohol 

 [54; B,]), and potash fusion of the 

 p-toluyl-o-benzoic acid thus formed 

 (Friedel and Crafts, Ann. Chim. [6] 14, 

 449 ; Bull. Soc. [2] 35, 508). 



By passing cyanic acid and hydrogen 

 chloride into toluene at 100 in presence 

 of aluminium chloride (Gattermann and 

 Rossolymo, Ber. 23, 1195). 



By passing carbon monoxide and 

 hydrogen chloride through toluene in 

 the presence of aluminium and cuprous 

 chlorides and oxidising the p-toluic 

 aldehyde thus formed (Gattermann and 

 Koch, Ber. 30, 1622). 



Paratoluic acid can be converted into 

 2-hydroxy-p-toluic acid (2-methylphenol- 

 4-carboxylic acid) by several processes : 



By sulphonation and potash fusion of 

 the 2-sulpho-acid (Weinreich, Ber. 20, 

 981). 



By conversion into 2-brom-p-toluic 

 acid (Bruckner, Ber. 9, 407) and potash 

 fusion of the latter (Vongerichten, Ber. 

 11, 368). 



By converting the acid (or nitrile) 

 into 2-nitro-p-toluic acid by nitration 

 (Fittig and Ramsay, Ann. 168, 251 ; 

 Banse, Ber. 27, 2162; Van Scherpen- 

 zeel, Loc. cit.}, reducing to amino-acid 

 and applying the diazo-reaction (Fittica, 

 Ber. 7, 927 ; Vongerichten and Rossler, 

 Ber. 11, 705). 



The 2-hydroxy-p-toluic acid thus 

 formed gives o-cresol when distilled 

 with lime. 



From Toluene through. m-Xylene and 

 the Hydroxytoluic Acids. 



Metaxylene is formed (among other 

 methylbenzenes) when methyl chloride 

 is passed into toluene in presence of 

 aluminium chloride (Friedel and Crafts, 

 Ann. Chim. [6] 1, 461 ; Ador and Ril- 

 liet, Ber. 11, 1627), and this on sul- 

 phonation gives (chiefly) m-xylene-4- 

 sulphonic acid (Jacobsen, Ann. 184, 



