62 A-C.] 



METACRESOL 



129 



and Kuhlberg, Ann. 155, 23 ; Ehrlich, 

 Ber. 15, 2009; Gattermann, Ber. 18, 

 1483), the latter converted into m- 

 nitrotoluene by the diazo-method (Ibid. 

 158, 346), reduced to m-toluidine, and 

 converted into m-cyanotoluene by the 

 diazo- (Sandmeyer) reaction (Buchka and 

 Schachtebeck, Ber. 22, 841), m-toluic 

 acid by hydrolysis, and then as above. 

 o-Nitrotoluene can be converted into 

 m-toluic acid by a similar series of pro- 

 cesses. 



Or p-toluidine can be sulphonated 

 (v. Pechmann, Ann. 173, 19.5; Nevile 

 and Winther, Ber. 13, 1947), the p- 

 toluidine-3-sulphonic acid converted into 

 the nitrile by Sandmeyer's process (Ran- 

 dall, Am. Ch. Journ. 13, 258), and the 

 latter hydrolysed to 3-sulpho-p-toluic 

 acid, which, by potash fusion, gives 3- 

 hydroxy-p-toluic = y-cresotic acid (We- 

 ber, Ber. 25, 1743). The latter on 

 heating- with hydrochloric acid is con- 

 verted into m-cresol. 



Or toluene can be converted into 3- 

 nitro-p-toluidine as above, the latter con- 

 verted into the nitrile (Leuckart,Ber.l9, 

 175 ; Niementowski and Rozanski, Ber. 

 21, 1993 5 Noyes, Am. Ch. Journ. 10, 

 476), then into 3-nitro-p-toluic acid by 

 hydrolysis, into 3-amino-p-toluic = 

 homoanthranilic acid by reduction, and 

 then into 3-hydroxy-p-toluic = y-cresotic 

 acid by the diazo-method (N. and R. 

 loc. cit. 1998). 



From toluene through p-xylene by 

 the action of sodium on p-bromtoluene 

 and methyl iodide (Fittig and Glinzer, 

 Ann. 136, 303 ; Jannasch, Ann. 171, 

 79), p-xylenesulphonic acid and 1:4:2- 

 xylenol ( Jacobsen, Ber. 11, 26 ; Wurtz, 

 Ann. 147, 373), 3-hydroxy-p-toluic acid 

 by potash fusion of latter (Jacobsen, 

 loc. cit. 570), and m-cresol as above. 



Or p-xylene may be nitrated, reduced 

 to the corresponding xylidine, the latter 

 converted into p-xylenol by the diazo- 

 method (Noelting, Witt, and Forel, Ber. 

 18, 2665), and then as above. 



NOTE: All generators of toluene thus become 

 generators of m-cresol. 



[B.] From acetone [108] through 

 mesitylene, mesitylenic acid (see under 

 o-cresol [61; B]), and m-xylene, and 



then as under A. Or from mesitylene 

 through uvitic acid and m-toluic acid 

 and then as under A (see also under o- 

 cresol [61 ; B]). 



Or from acetone through phorone, 

 pseudocumene, I : 3-dimethyl-4-benzoic 

 (xylic) acid, and m-xylene as under o- 

 cresol (61; B). 



NOTE : Generators of mesitylene and uvitic 

 acid (see under benzyl alcohol [54 ; D to Q,]) 

 thus also become generators of m-cresol. 



From acetone and oxalic acid [Vol. II] 

 and ethyl alcohol [14] through acetone- 

 oxalic ester by the action of sodium 

 ethylate on a mixture of acetone and 

 oxalic ester (Claisen and Stylos, Ber. 

 2O, 2188). This acetoneoxalic ester 

 ( = acetylpyroracemic ester) on heating 

 with baryta water is converted into 

 5-hydroxy-m-toluic acid (Claisen, Ber. 

 22, 3271), from which m-cresol can be 

 obtained as under A. 



[C.] From acetic acid [Vol. II] and 

 ethyl alcohol [14] through 5-methyl- 

 phenol-2 : 4-dicarboxylic acid ( m- 

 hydroxyuvitic acid) by the action of 

 chloroform, chloral, trichloracetic ester 

 or carbon tetrachloride on sodio-aceto- 

 acetic ester (Oppenheim and Pfaff, Ber. 

 7, 929 ; 8, 884; Oppenheim and Precht, 

 Ber. 9, 321 ; Conrad and Guthzeit, 

 Ann. 222, 249), and hydrolysis of the 

 ester thus formed. The acid on distil- 

 lation with baryta gives m-cresol (Op- 

 penheim and Pfaff, Ber. 8, 886). 



Or acetoacetic ester on treating the 

 sodium compound with methylene iodide 

 (Hagemann, Ber. 26, 876), or the ester 

 with formic aldehyde (Knoevenagel, 

 Ibid. 1090) and hydrolysis of the pro- 

 duct, gives 3-methyl-A 2 -keto-R-hexene 

 (i - methylcyclo - 3 - hexenone) (Hage- 

 mann, loc. cit. ; Knoevenagel, loc. cit. 

 1085; K. and Klages, Ann. 281,97). The 

 latter forms a dibromide (Hagemann, 

 loc. cit. 884 ; Knoevenagel, loc. cit. 

 1951), which readily decomposes into 

 hydrogen bromide and m-cresol (K. 

 Ibid.}. 



Acetoacetic ester through its methyl- 

 ene derivative can also be converted by 

 the action of ammonia under various 

 conditions into dihydrolutidine-dicarb- 

 oxylic ester (Knoevenagel and Klages, 



