Water → tert-Butyl 4-ethyl-3-oxopiperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a slurry of tert-butyl 3-oxopiperazine-1-carboxylate (10 g, 49.9 mmol) in 250 mL of DMF, NaH (60% in mineral oil) (2.1 g, 52.4 mmol) was added in portions. The mixture was stirred for 15 min after completion of addition, cooled to 0° C. and iodoethane (5.62 mL, 69.92 mmol) slowly added over 3 min. The resultant suspension was stirred at rt for 2 h. Water was slowly added (400 mL) and then 250 mL of 1:1 ethyl acetate:diethyl ether. The layers were separated and then the organic phase was washed with brine, dried over sodium sulfate, filtered and concentrated to afford tert-butyl 4-ethyl-3-oxopiperazine-1-carboxylate as a colorless oil weighing 6.4 g which was used directly in the next step.

Provenance & Evidence