N,N-Dimethylaniline CAS:121-69-7

N,N-Dimethylaniline is used in production of dyestuffs, as a solvent, a reagent in methylation reactions, and a hardener in fiberglass reinforced resins.

N,N-dimethylaniline is an important dye intermediate. It can be used to prepare alkaline yellow, Crystal Violet 5BN, basic magenta green, basic lake blue BB, basic brilliant blue R, cationic red 2BL, brilliant red 5GN, violet 3BL, brilliant blue, etc. In the pharmaceutical industry, the product can be used to manufacture cefazolin V, sulfamonomethoxine, Sulfadoxine, fluorocytosine, etc. moreover, It can be used as an intermediate to vanillin, a stabilizer for colorimetric peroxidase determination or as a reagent in chemical synthesis.

N,N-Dimethylaniline is a light yellow to light brown oily liquid. Has a pungent odor. Soluble in ethanol, chloroform, ether and aromatic organic solvents, slightly soluble in water.It is a tertiary amine used in the synthesis of several triarylmethane dyes like malachite green. It is also used in the synthesis of a magnetic gram stain for the detection of bacteria.

Primary and secondary amines (including aniline and monomethylaniline) can be removed by refluxing for 4-5hours with excess acetic anhydride, and then fractionally distilling. Crocker and Jones (J Chem Soc 1808 1959) used four volumes of acetic anhydride, then distilled off the greater part of it, and dissolved the residue in ice-cold dilute HCl. Non-basic materials were removed by ether extraction, then the dimethylaniline was liberated with ammonia, extracted with ether, dried, and distilled under reduced pressure. Metzler and Tobolsky (J Am Chem Soc 76 5178 1954) refluxed with only 10% (w/w) of acetic anhydride, then cooled and poured it into excess 20% HCl, which, after cooling, was extracted with diethyl ether. (The amine hydrochloride remains in the aqueous phase.) The HCl solution was cautiously made alkaline to phenolphthalein, and the amine layer was drawn off, dried over KOH and fractionally distilled under reduced pressure, under nitrogen. Suitable drying agents for dimethylaniline include NaOH, BaO, CaSO4, and CaH2. Other purification procedures include the formation of the picrate (m 163o from Me2CO or EtOH/H2O), prepared in *benzene solution and crystallised to constant melting point, then decomposed with warm 10% NaOH and extracted into ether: the extract was washed with water and distilled under reduced pressure. The oxalate salt has also been used for purification. The base has been fractionally crystallised by partial freezing and also from aqueous 80% EtOH then from absolute EtOH. It has been distilled from zinc dust, under nitrogen. [Beilstein 12 H 141, 12 I 151, 12 II 2, 12 III 245, 12 IV 243.]