Hydrochloric Acid → HCID 11493135, compound

Participants

Reaction Conditions

Reaction Steps

A solution of (2RS,3RS)-3-(2,3-dihydro-4H-1,4-benzoxazin-4-yl)-2-hydroxy-N-methyl-3 phenylpropanamide (216 mg, 0.692 mmol) in dry tetrahydrofuran (3 mL) under nitrogen was treated dropwise with a solution of borane (1.0 M in tetrahydrofuran, 3.50 mL, 3.50 mmol), and the resulting solution was stirred at 70° C. for 2 hours. After cooling in an ice bath, the reaction mixture was treated with a 2N aqueous solution of hydrochloric acid (1 mL), and the resulting mixture was heated at 50° C. for 30 minutes. Tetrahydrofuran was removed under reduced pressure, and the aqueous residue was dissolved in water (5 mL) and washed with diethyl ether (10 mL). The aqueous layer was made alkaline with solid potassium carbonate and extracted with ethyl acetate (2×10 mL). The combined organic extracts were washed with brine, dried (sodium sulfate) and concentrated under reduced pressure to yield 202 mg (98%) (1RS,2SR)-1-(2,3-dihydro-4H-1,4-benzoxazin-4-yl)-3-(methylamino)-1-phenylpropan-2-ol as a colorless oil. This oil was dissolved in ethanol (1 mL) and treated with a solution of hydrochloric acid (0.5 mL, 4M in 1,4-dioxane). All volatiles were again removed under reduced pressure. The resulting white solid was recrystallized (minimal warm ethanol/ethyl ether/−20° C.) to yield 105 mg (41%) (1RS,2SR)-1-(2,3-dihydro-4H-1,4-benzoxazin-4-yl)-3-(methylamino)-1-phenylpropan-2-ol dihydrochloride as a white solid. MS (ESI) m/z 299.0 ([M+H]+);

Provenance & Evidence