Sulfuric Acid → 3-Phenylisoserine, (2R,3S)-

Participants

Reaction Conditions

Reaction Steps

(2R,3S)-3-phenyl-isoserinamide (200 mg, 1.11 mmol), as prepared in Example 32, was combined with 354 mg (1.12 mmol) of Ba(OH)2 ·8H2O and water (2 ml). The resulting suspension was heated to reflux for nine hours. After the reaction mixture was cooled to 80° C., 15 ml of water was added to the solution. The temperature of the solution was maintained at 80° C. for 20 minutes before a solution of 110 mg, 1.11 mmol of concentrated sulfuric acid in 1 ml of water was added. A white precipitate appeared in the solution which was determined to have a pH of between 5 and 7. Heating at 80° C. was maintained for another 20 minutes, and the mixture was then cooled to room temperature. The resulting precipitate (BaSO4) was centrifuged to the bottom of the container, the supernatant was separated, and solvent was removed under vacuum. The resulting white solid was extracted with acetone and collected by filtration to provide 148 mg of the title compound, for a yield of 74%. The material melted with decomposition at 238° C. The 1H NMR (D2O/NaOD) data were as follows: δ 3.94 (d, J=3.9 Hz, 1H), 4.01 (d, J=3.9 Hz, 1H), 7.0-7.5 (aromatic, 5H). Analytical for C9H11NO3 : Calculated: C, 59.66; H, 6.07, N, 7.73. Found: C, 59.10; H, 6.11; N, 7.61.

Provenance & Evidence