Water → HCID 19362820, compound

Participants

Reaction Steps

To a solution of the mixture of oxime isomers 8 (4.92 g, 16.2 mmol) in 75 ml THF (freshly distilled from sodium benzophenone ketyl) under nitrogen was added borane-tetrahydrofuran complex (1.0M in THF, 55.0 ml, 55.0 mmol) by syringe at room temperature. The resulting pale orange solution was brought to reflux and held there for 16 hours. With cooling by an ice bath, water (125 ml) was carefully added to quench, followed by 20% NaOH (125 ml).The resulting biphasic solution was refluxed with vigorous magnetic stirring overnight. After cooling to room temperature, hexanes (60 ml) were added and the layers were separated. The aqueous portion was extracted with hexanes (2×50 ml). The combined organic portions were dried over potassium carbonate and concentrated in vacuo to a cloudy, colorless syrup. This syrup was purified by column chromatography on 20 g neutral alumina (activity I) using a 20% ethyl acetate-hexanes to 4% diethylamine-chloroform elution gradient. The amine 13 was isolated as 3.985 g of a clear, colorless syrup (89% yield): Rf 0.18 (2% diethylamine in CHCl3); 1H NMR (CDCl3) δ7.41 (d, J=8.2 Hz, 2H), 7.35-7.28 (m, 5H), 7.03 (d, J=8.2 Hz, 2H), 4.18 (dd, J=8.2, 5.3 Hz, 1H), 2.97 (dd, J=13.3, 53 Hz, 1H), 2.83 (dd, J=13.3, 8.3 Hz, 1H), 1.45 br s, 2H); low resolution mass Spec. 277 (M+, 1.5), 275 (M+, 1.5), 261 (2.2), 259 (2.2), 171, (4.5), 169 (4.5), 106 (100), 79 (45).

Provenance & Evidence