1-Methylimidazole → Fosmetpantotenate

Participants

Reaction Conditions

Reaction Steps

L-alanine methyl ester hydrochloride (1.35 g, 9.65 mmol) was suspended in dichloromethane (20 mL) and treated with phenyl phosphodichloridate (1.51 mL, 10.15 mmol) at −78° C. under an atmosphere of argon. Diisopropylethylamine (2.6 mL, 20.27 mmol) was added dropwise. The mixture was stirred at −78° C. for 30 minutes, then allowed to warm to room temperature for 1 hr. The mixture was chilled to −5° C. and methyl pantothenate (1.6 mL, 20.27 mmol) was added dropwise in dichloromethane. N-methylimidazole (1.6 mL, 20.27 mmol) was added, and after stirring at −5° C. for 30 mins and room temperature for 1 hour, 2 mL of methanol was added. The mixture was washed sequentially with water (30 mL), 5% citric acid (30 mL), and brine (10 mL). The organic phase was dried (Na2SO4) and the solvent was removed under reduced pressure. Purification was achieved with a 1:1 mixture of EtOAc:hexane to afford the product as a clear colorless oil. (1.1 g, 24% yield). HPLC showed the product, as a 1:1 mixture of disastereomers, having a purity of 97%. 1H NMR (300 MHz, CDCl3): δ 1.11 (s, 3H, CH3), 1.27, 1.39 and 1.40 (2 Ss, 3H, CH3), 1.41 (overlapping d, 3H, J=1.2 Hz, CHCH3), 3.55 (m, 2H, CH2), 3.60 (m, 1H, CH2), 3.63 (m, 1H, CH), 3.66 and 3.68 (2 Ss, 3H, COCH3), 3.70 and 3.74 (2 Ss, 3H, COCH3), 3.78 (m, 1H CH), 4.03 (m, 1H, CH), 4.17 (m, 1H, CH), 7.16 and 7.35 and 7.40 (2 Ms, 5H, Ph). Expected Mol. Wt. 474.18, Observed Mol. Wt. 475.03 (M+H+].

Provenance & Evidence