Triethylamine → Tert-butyl 4-(2-(methylsulfonyloxy)ethyl)piperazine-1-carboxylate

Participants

Reaction Steps

To a solution of tert-butyl 4-(2-hydroxyethyl)piperazine-1-carboxylate (1.7 g, 7.4 mmol) and Et3N (1.12 g, 11.1 mmol) in dichloromethane (20 mL) was added methanesulfonyl chloride (1 g, 8.87 mmol) at 0° C. The mixture was stirred at room temperature for 3 h. The mixture was washed with brine. The organic layer was concentrated in vacuo to give crude tert-butyl 4-(2-(methylsulfonyloxy)ethyl)piperazine-1-carboxylate (2.1 g, 94%). This was used in the next step without purification. 1H NMR (300 MHz, CDCl3): δ 4.38 (t, 2H, J=5.3 Hz), 3.49-3.44 (m, 4 h), 3.09 (s, 3H), 2.79 (t, 2H, J=5.1 Hz), 2.58 (t, 4 h, J=5.0 Hz), 1.49 (s, 9H). LCMS: No molecular ion observed for desired mass.

Provenance & Evidence