tert-butyl 2-(2-ethoxy-2-oxoethyl)-3-oxopiperazine-1-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1N Sodium hydroxide (11.4 mL, 11.4 mmol) was added to 2-ethoxycarbonylmethyl-3-oxo-piperazine-1-carboxylic acid tert-butyl ester (2.5 g, 8.73 mmol) in methanol (20 mL) at room temperature and then stirred for 2.5 hours. The reaction mixture was concentrated, acidified with 2N HCl to pH˜2 and extracted with dichloromethane (3 times). The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated to afford the titled compound (1.87 g, 83%, white foam solid). 1H NMR (CDCl3) δ (ppm): 7.68 (bs, 1H), 4.78 (m, 1H), 4.19 (m, 1H), 3.45 (m, 1H), 3.34 (m, 2H), 2.97 (m, 2H), 1.49 (s, 9H). The reaction mixture was concentrated extracted with dichloromethane (3 times) The organic layer was washed with brine dried over anhydrous sodium sulfate filtered concentrated