Acetic Acid → HCID 86619835, compound

Participants

Reaction Steps

(R)-Valine t-butyl ester (4.9 g; 28.28 mmol) was dissolved in methanol (100 ml). Acetic acid (1.62 ml; 28.28 mmol) and (1,3-dioxo-1,3-dihydroisoindol-2-yl)-acetaldehyde (5.40 g; 28.28 mmol) were added thereto. Then, sodium cyanoborohydride (1.95 g; 31.11 mmol) dissolved in THF (20 ml) was added. The mixture was stirred at RT for 6 h and then saturated NaHCO3 solution (200 ml) was added. Methanol was removed under reduced pressure, and the residue was extracted with EtOAc (3×; 100 ml). The combined organic phases were dried over MgSO4. Removal of the solvent under reduced pressure and purification of the residue by column chromatography (SiO′) resulted in t-butyl (R)-2-(2-(1,3-dioxo-1,3-dihydroisoindol-2-yl)ethylamino)-3-methylbutyrate (6.60 g; 19.05 mmol). MS: 347.20 (M+H); Rt: 1.02 min (method: gradient 0 min 96% H2O (0.05% TFA) 2.0 min 95% acetonitrile, 95% acetonitrile to 2.4 min, 4% acetonitrile 2.45 min; flow rate 1 ml/min; column 0.4 μL (YMC J'sphere ODS H80 20X2 1.4μ); 30° C.)

Provenance & Evidence