Benzyl Bromide → 5-Benzyl-7-t-butoxycarbonylamino-4-oxo-7-methyl-5-azaspiro[2.4]heptane

Participants

Reaction Steps

To a solution (65 mL) of 7-(tert-butoxycarbonylamino)-7-methyl-5-azaspiro[2.4]heptan-4-one (3.12 g, 12.97 mmol) in dimethylformamide in an ice bath was gradually added sodium hydride (55%, dispersion in a mineral oil, 538 mg, 12.33 mmol) in 5 minutes, and the mixture was stirred at the same temperature for 40 minutes. Benzyl bromide (1.851 mL, 15.56 mmol) was added, and the mixture was stirred at room temperature for 1.5 hours. The reaction mixture was diluted by adding ethyl acetate (300 mL), and the solution was washed with water (100 mL×2) and saturated aqueous solution of sodium chloride (100 mL). After drying the solution with anhydrous sodium sulfate and removing the dessicating agent by filtration, the solvent was removed by distillation under reduced pressure. The residue was purified by silica gel column chromatography (hexane : ethyl acetate, 9:1→4:1→2:1) to obtain 4.20 g (12.71 mmol, 98%) of the target compound as a colorless transparent gummy solid.

Provenance & Evidence