N-Methyl-1 ,2-diphenylethylamine AND HYDROCHLORIDE

Submitted by Robert Bruce Moffett.1 Checked by N. J. Leonard and L. A. Miller. 

N-Benzylidenemethylamine. A solution of 31.9 g. (0.3 mole) of benzaldehyde in 80 ml. of benzene contained in a 300-ml. round-bottomed flask is cooled to approximately 10°. To this is added a solution of 14 g. (0.45 mole) of anhydrous methylamine in 50 ml. of benzene (Note 1). On standing, the solution becomes warm and turns milky. After 1 hour the flask is connected to a Dean-Stark water separator 1 which is attached to a reflux condenser, and the solvent is caused to reflux until no more water separates (Note 2). The water separator is then replaced by an 8-in. Vigreux column (Note 3), and the solution is distilled under reduced pressure. After removal of the solvent, the product distils at 92-93°/34 mm. The yield is 31-34 g. (87-95%) of colorless liquid, d5 1-5497, tt 1.5528. 

N-Methyl-, 2-diphenylethylamine hydrochloride. Hydrogen chloride gas (Note 4) is passed into a stirred solution of 30 g. (0.14 mole) of N-methyl-l,2-diphenylethylamine in 500 ml. of anhydrous ether until saturated or until a drop of the ether on moistened pH test paper indicates that it is strongly acid. The hydrochloride separates as a colorless crystalline precipitate. It is collected on a suction filter, washed with ether, and dried. The yield is 34.2-35.1 g. (97.5-100%), and the product is practically pure, m.p. 184-186°. If desired it can be recrystallized by dissolution in a little methanol followed by addition of absolute ether. 

The collection of the theoretical amount of water (about 5.4 ml.) requires approximately 3 hours. 

For the preparation of N-methyl-l,2-diphenylethylamine it is not absolutely necessary to distil the N-benzylidenemethyl-amine. The dried benzene solution can be used directly. 

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N-Methyl-1,2-diphenylethylamine AND HYDROCHLORIDE, 34, 64 2-Methyldodecanoic acid, 38, 43, 47, 49 2-Methyl-2-dodecenoic acid, 38, 49,50 trans-2-Methyl-2-dodecenoic acid,... 

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