Methanol → HCID 59164823, compound

Participants

Reaction Steps

To a solution of methyl(5R)-5-{4-[(phenylmethyl)oxy]phenyl}-L-prolinate (120 mg, 0.38 mmol) in THF (2.3 ml) was added LiOH monohydrate (26 mg, 0.61 mmol) dissolved in water (1.1 ml), followed by methanol (1.1 ml). The resulting solution was stirred at room temperature for 2.5 hours, then left overnight at −18° C. Then the organic solvent was evaporated under reduced pressure maintaining the temperature at 38° C. and the aqueous residue containing the acid intermediate (Rt (HPLC)=3.63 min. MS: (ES/+) m/z: 298 [MH+]. C18H19NO3 requires 297) was treated with BOC2O (168 mg, 0.77 mmol) dissolved in THF (1.1 ml). The reaction mixture was stirred at room temperature for 3.5 hours. The organic solvent was evaporated and the basic aqueous solution was acidified at 0° C. with aqueous 1N HCl solution to pH=3, this acidic aqueous solution was extracted with ethyl acetate (2×10 ml). The organic phase dried over Na2 SO4 and evaporated under reduced pressure gave a solid, which was titurated in n-hexanes (3×6 ml) affording the title compound as a white powder (137 mg, 90% for two steps); Rt (HPLC): 5.81 min; Rf (cyclohexane:ethyl acetate=1:1): 0.34; MS: (ES/+) m/z: 420 [M+Na+]C23H27NO5 requires 397; MS: (ES/−) m/z: 396 [M-H]C23H27NO5 requires 397; 1H NMR (300 MHz, CDCl3) δ(ppm): 7.5-7.3 (m, 5H), 7.10 (bm, 2H), 6.90 (d, 2H), 5.08 (s, 2H), 4.65 (bm, 1H), 4.50 (bm, 1H), 2.58 (bm, 1H), 2.31 (bm, 1H), 2.11-1.90 (m, 2H), 1.16 (s, 9H).

Provenance & Evidence