Ethanolamine → Dihydrothebaine

Participants

Reaction Conditions

Reaction Steps

Thebaine (4.0 g dry basis, 12.9 mmol) in mixture of 2-ethoxyethanol (13.0 g) and ethanolamine (1.3 g, 21.3 mmol, 1.65 equiv) and is heated at 110 to 114° C. p-Toluenesulfonylhydrazide (4.8 g, 25.8 mmol, 2.0 equiv) is dissolved at 15 to 25° C. in a mixture of ethanolamine (9.6 g, 157.2 mol, 12.2 equiv) and 2-ethoxyethanol (0.8 g) and the solution is added in portions to the thebaine mixture over 1 hour 10 minutes while maintaining the batch temperature in the range 110 to 118° C. The reaction mixture is held at 110 to 114° C. for 1.5 h then cooled to 19° C. and water (24 g) added in two portions while maintaining the batch temperature at ≦30° C. The resulting slurry (pH 10.9) is stirred and further cooled to 0 to 5° C. and then filtered. The product washed with water (3×8 g) and dried at 40° C. to a constant weight to give 8,14-dihydrothebaine (3.64 g, 90.3% yield; 98.5 area % purity by HPLC).

Provenance & Evidence