Ammonium Chloride → HCID 178451026, compound

Participants

Reaction Steps

A mixture of tert-butyl (4R)-4-(benzyloxycarbonylamino)-4-cyanobutyrate (1.53 g, 4.8 mmol), ammonium chloride (0.28 g, 5.2 mmol), sodium azide (0.345 g, 5.3 mmol) and dry DMF (6 ml) was stirred and heated at 90°-95° C. under argon for 20 hours. The mixture was cooled and concentrated and the residue partitioned between ice-cooled water (40 ml) and ethyl acetate (30 ml) with the pH of the aqueous phase being adjusted to 3 by the addition of 10% aqueous citric acid solution (ca. 10 ml). The aqueous layer was extracted with further ethyl acetate (3×30 ml) and the combined organic solution washed with water (4×25 ml), dried (MgSO4) and evaporated. A solution of the residue in dichloromethane (3 ml) was added dropwise to stirred hexane (20 ml) and the precipitate was collected, washed with hexane and dried to give tert-butyl (4R)-4-(benzyloxycarbonylamino)-4-(tetrazol-5-yl)butyrate (1.462 g, 84%), m.p. 99°-101° C.

Provenance & Evidence