Methylation of aromatic amines by the Wallach method was written by Borkowski, Walter L.;Wagner, E. C.. And the article was included in Journal of Organic Chemistry in 1952.Quality Control of 2-Chloro-N,N-dimethylaniline This article mentions the following:
The methylation of PhNH2, o- (I) and p-MeC6H4NH2 (II), 5,2-BrMeC6H3NH2 (III), o-ClC6H4NH2 (IV), and 2,6- (V) and 2,4-xylidine (VI) with (HCHO)n and HCO2H, HCl, HBr, or AcOH, or without acid shows that, without acid, only negligible condensation takes place. Heating PhNMe2, (HCHO)n, and 98% HCO2H (1:1:1) 1 h. gives 92% (p-Me2NC6H4)2CH2, m. 85-6°; p-MeC6H4NMe2, (HCHO)n, and HCO2H (1:1:1), heated 3.5 h., give 98% [5,2-Me(Me2N)C6H3]2CH2. Heating V, (HCHO)n, and HCO2H (1:3:3) 0.5 h. gives 33% 2,6-Me2C6H3NMe2, b. 194-9°, and 63% diphenylmethane base, b0.8 170.5°, m. 49.5-50.5°, resolidifying and m. again 60-60.5°; 2,6-Br2C6H3NH2 (VII), (HCHO)3, and HCO2H (1:3:8), heated 3 h., give 83% [3,5,4-Br2(H2N)C6H2]2CH2, m. 159-60°; m-O2NC6H4NH2 (VIII), (HCHO)n, and HCO2H (1:2.6:4), heated 10.5hrs., give [4,2-Me2N(O2N)C6H3]2CH2, m. 191-2°. II, (HCHO)n, and HCO2H (1:3:3), heated 0.5 h., give a trace of p-MeC6H4NMe2 and 10% 3-p-tolyl-6-methyl-3,4-dihydroquinazoline, m. 156.5-7°. VI (0.2 mol.) added to (HCHO)n and HCO2H (1:3:3)reacts vigorously; when the mixture is heated 0.5 h. 33% 2,4-Me2C6H3NMe2 and an unidentified compound, b0.8 186-7°, m. 165-6°, are formed. Similarly, 2,4-Cl2C6H3NH2 (IX), (HCHO)n, and HCO2H (1:3:3) give 84% 2,4-Cl2C6H3NMe2, m. 169.5-70.5°, which is changed when refluxed with Ac2O alone or with C5H5N. The rate of methylation is measured by determining the CO2 formed. After an extensive study of the effect of the amount of HCHO, of H2O, of variation in the amounts of HCO2H, of strong acids, of the order of mixing the reagents, and of agitation, the results of which are given in 5 tables, a modified procedure for the Wallach methylation of aromatic amines is given: 1 mol. amine is added gradually to a gently warmed and stirred mixture of 2.5 mols. (HCHO)n and 3 mols. HCO2H, the mixture heated 5 min. on a steam bath, poured into ice-cold NaOH (1.3 equivalents to 1 of the HCO2H) and Na2SO3 (1.2 equivalents to 1 of the HCHO), the solution steam-distilled, and the distillate extracted with ether. In this way the following amines give the corresponding N,N-di-Me derivatives (% yield): 1 40, II 50, IV 23, p-isomer 65, VI 65, V 97, p-O2NC6H4NH2 50, p-MeOC6H4NH2 50, mesidine 98, IX 92, VII 92, 2,4-MeBrC6H3NH2 98, 2,4,6-Br3C6H2NH2 98, o-MeC6H4NHMe 55, p-isomer 95, 2,4-Me2C6H3NHMe 98, 2,6-isomer 98. PhNH2, m-MeC6H4NH2, 1- and 2-C10H7NH2, p-H2N’C6H4SO3H, VIII, PhNHMe, and m-MeC6H4NHMe are not methylated by this procedure. The primary and secondary amines successfully methylated all have 1 or more of the o- and p-H atoms replaced. With all reactive positions unsubstituted, the nuclear condensations predominate; with 1 or 2 reactive positions blocked, methylation reaches 90%; with all reactive positions blocked, methylation is almost 100%. In the experiment, the researchers used many compounds, for example, 2-Chloro-N,N-dimethylaniline (cas: 698-01-1Quality Control of 2-Chloro-N,N-dimethylaniline).
2-Chloro-N,N-dimethylaniline (cas: 698-01-1) belongs to organic chlorides. Organic chlorides can be used in production of: PVC, pesticides, chloromethane, teflon, insulators. Aryl chlorides may be prepared by the Friedel-Crafts halogenation, using chlorine and a Lewis acid catalyst.Quality Control of 2-Chloro-N,N-dimethylaniline
Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics