Hydrogen Bromide → HCID 2734540, compound

Participants

Reaction Steps

A solution of D-ornithine hydrochloride (35 g, 0.208 mol) in water (350 ml) was treated with copper (II) sulphate (16.6 g, 0.104 mol). 5M Potassium hydroxide (ca. 40 ml) was added to pH 3 then N-carboethoxyphthalimide (45.5 g, 0.208 mol) was added and the pH maintained at 9-10 by the addition of 5M potassium hydroxide (ca.55 ml). After 2 h, 48% hydrobromic acid was added to pH 0.4 (ca. 77 ml) and any resulting precipitate removed by filtration. The filtrate was cooled to <5° C., then treated with further hydrobromic acid (152 ml) and potassium bromide (59 g, 0.5 mol). The mixture was then treated dropwise over 45 min with a solution of sodium nitrite (28.6 g, 0.41 mol) in water 275 ml) whilst maintaining a temperature <5° C. The mixture was then stirred at <5° C. overnight. The resulting precipitate was then removed by filtration, dissolved in ethyl acetate (400 ml) and the solution washed with water (2×200 ml) and brine (200 ml), dried (MgSO4) and evaporated in vacuo to provide the title compound (40.6 g, 47%) as a cream solid.

Provenance & Evidence