Ammonia → 1,3-Benzenedimethanamine

Beteiligte Stoffe

Reaktionsschritte

1-(Dihexadecyl)aminomethyl-3-cyanobenzene (1,814 g.) was placed in an autoclave (15 gal.) with a mixture of hexane (1.98 l.), ethanol (17.82 l.) and ammonia (3,627 g.). Said mixture was prepared in advance by saturating the ethanol-hexane mixture with ammonia gas. The saturated mixture was refrigerated until it was ready for use. Raney nickel (3,689 g., wet weight) was added. The Raney nickel W2 is weighed as a wet slurry, the form in which it is obtained from W. R. Grace as Raney nickel No. 28. This differs from the standard W2 Raney nickel in that it is slurried in water rather than benzene. For the present process, the difference is inconsequential. The mixture was contacted with hydrogen gas maintained at a pressure of 50 psig. for four hours at room temperature. After the uptake of hydrogen ceased, the mixture was filtered and the filtrate concentrated to an oil by vacuum distillation. The oil was dissolved in methylene chloride (4.0 l.) and washed once with water (2.0 l.) and three times with a saturated sodium chloride solution (1.0 l.). The clear methylene chloride solution was then dried over magnesium sulfate (454 g.), filtered and concentrated to an oil again to yield 1-dihexadecyl)aminomethyl-3-aminomethylbenzene (1,236 g., 68% yield). The purity of the product was determined by thin layer chromatography. The dihydrochloride salt was prepared by dissolving the 1-(dihexadecyl)aminomethyl-3-aminomethylbenzene (1,236 g.) in ethanol (5.0 l.) and ethanol (5.0 l.) containing dissolved hydrogen chloride gas (800 g.) was added. The mixture was stirred for one hour at room temperature and the solvent removed by vacuum distillation. Ether (8.0 l.) was added to the residue until a clear solution was obtained. Cooling with a dry ice/acetone bath followed by the slow addition of acetonitrile effected the precipitation of 1-(dihexadecyl)aminomethyl-3-aminomethylbenzene diamine dihydrochloride as a fine white crystalline material. The overall yield for the two processes was 62.5%.

Herkunft & Nachweise