N-tert-butyl-2-(3-azido-2-oxo-5-phenyl-2,3,4,5-tetrahydro-1H-(1)benzazepin-1-yl) ethanoic acid amide → N-tert-butyl-2-(3-amino-2-oxo-5-phenyl-2,3,4,5-tetrahydro-1H-(1)benzazepin-1-yl) ethanoic acid amide

Participants

Reaction Steps

The crude product from the previous displacement reaction, N-tert-butyl-2-[3-azido-2-oxo-5-phenyl-2,3,4,5-tetrahydro-1H-(1)benzazepin-1-yl] ethanoic acid amide, (8.58 g, 19.37 mmoles), was dissolved in 75 ml methanol under nitrogen. The catalyst, 6 g of 5% Pd/C, 50% w/w, was added and the mixture was hydrogenated at 55 psi H2 for 5 hours. The mixture was filtered through Celite® and the catalyst washed three times with methanol and the filtrate evaporated. TLC (24:1, methylene chloride: methanol, silica gel), showed less polar material and the product at Rf 0.25. The crude product taken up in ethyl acetate and extracted with acid. The acidic extract was back washed with ethyl acetate and then the aqueous fraction was taken with fresh ethyl acetate and the pH adjusted to 10.0. The organic fraction was then dried with brine and sodium sulfate, filtered and concentrated, yielding 1.832 g (25.8%) of the crystalline amine (mp 189°-192° C., one diastereomer). The mother liquor yielded 1.545 g (21.8%) of a foam upon stripping the solvent, which contained nearly a 1:1 mixture of the diastereomers.

Provenance & Evidence