Pyridine → HCID 86629197, compound

Participants

Reaction Steps

To a suspension of (+)-carbobenzyloxy-D-proline (10 g, 40 mmol) in dichloromethane (250 mL) was added oxalyl chloride (6.9 mL, 80 mmol) followed by dimethyl formamide (15 μL, 0.2 mmol). The reaction mixture was then stirred for 2 h and concentrated in vacuo. The resulting acid chloride in dichloromethane (50 mL) was added to a mixture of magnesium chloride (4 g, 40 mmol) and tert-butyl acetoacetate (6.5 mL, 4 mmol) in pyridine (6.5 mL, 80 mmol) and dichloromethane (50 mL) at 0° C. and stirred for 30 min. The reaction mixture was then stirred at room temperature for 16 h and then diluted with EtOAc (25 mL). The organic layer was washed with 10% HCl solution (1×250 mL), saturated NaHCO3 solution (1×250 mL) and then brine (1×250 mL). The separated organic layer was then dried over Na2SO4 and concentrated in vacuo to afford (2R)-benzyl 2-(2-(carbonyl)-3-oxobutanoyl)pyrrolidine-1-carboxylate. LCMS: 6.51 min, calculated: 389, found (MH+): 390.

Provenance & Evidence