Aniline, C 6 H 5 NH 2, monomethyl aniline, C 6 H 5 NH CH 3, and dimethyl aniline, C 6 H 5 N(CH 3) 2, are in increasing order of basicity.
This is dissolved in cold concentrated sulphuric acid, in which it forms a yellowish red solution, but on heating to ioo° C. the colour changes to red and violet, and on pouring out upon ice, the monomethyl ether of alizarin is precipitated.
Ital., 1887, 17, p. 126; 1888, 18, p. 457) synthesized the asparagines from the monomethyl ester of inactive aspartic acid by heating it with alcoholic ammonia.
Monomethyl and dimethyl aniline are colourless liquids prepared by heating aniline, aniline hydrochloride and methyl alcohol in an autoclave at 220°.
Monomethyl aniline boils at 193-195'; dimethyl aniline at 192°.