Dimethyl-a-naphthylamine

XIV. Treatment with Franchimont Reagent. Mix in a test tube ca O.lg of the sample with ca 5ml of glac AcOH and add 2 drops of dimethyl-a -naphthylamine. Add ca 0.2g of Zn dust and allow to stand for 2 mins. A brn-red color confirms the presence of DlNA(See also Chart B)... 

A mixture of 171 g. (1 mole) of dimethyl-a-naphthylamine (Note 1) and 125 g. (1.2 moles) of cyanogen bromide 1 in a 1-1. flask (Note 2) is heated under reflux on the steam bath for 16 hours (Note 3). The cooled reaction mixture is added to 2.5 1. of dry ether, and the insoluble quaternary salt (Note 4) is filtered. The ether filtrate is extracted with four 800-ml. portions of approximately 15% hydrochloric acid solution (Note 5) and washed with five 500-ml. portions of water. The ether solution is dried with 30-35 g. of anhydrous calcium sulfate (Drierite). After filtration, the solvent is removed by distillation at atmospheric pressure on the steam bath the residue is fractionated under reduced pressure. The yield of pale yellow oil, boiling at 170-171°/ mm- (185—187°/3 mm.), amounts to 115-122 g. (63-67%) (Note 6). 

About 25 g. of crystalline dimethyl-a-naphthylamine hydrochloride may be recovered by efficient chilling of the hydrochloric acid extracts. 

SYNS l-DIMETHYLAMINONAPHTHALENE DIMETHYL-a-NAPHTHYLAMINE tt-DIMETHYL-NAPHTHYLAMINE N,N-DLMETHYL-a-NAPHTHYL-AMINE... 

DIMETHYL-3-(2-NAPHTHALENYL)(2R,3S)-REL-3-PYRROUDINOL DROCHLORIDE see DSU300 N,N-DIMETHYL-l-NAPHTHYLA. flNE see DSU400 DIMETHYL-a-NAPHTHYLAMINE see DSU400 a-DIMETHYLNAPHTHYLAMINE see DSU400... 

For colorimetric assay, although the diazo compound can be coupled with A -(l-naphthyl)ethylenediamine (see Sulphonamides, p. 609) Dewing and Foster found that for routine assay a more satisfactory determination could be carried out if the acid hydrolysate were treated with sodium nitrite and coupled with dimethyl-a-naphthylamine. 

Prepare a series of standard solutions containing 1 to 0 5 mg of 4,4 -diaminodiphenyl sulphone in 100 ml by suitably diluting with water a 1 per cent solution in dilute hydrochloric acid. Treat 10 ml of each standard solution successively with 0 4 ml of concentrated hydrochloric acid, 1 ml of 0 1 per cent sodium nitrite solution, 10 ml of ethanol and 1 ml of a 1 per cent ethanolic solution of dimethyl-a-naphthylamine. Mix thoroughly and after ten minutes measure the extinction at the absorption maximum at about 550 m/u. Prepare a standard curve from the readings obtained. 

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