Formaldehyde → 4-(t-Butoxycarbonyl)-1-methylpiperazine-2-carboxamide

Participants

Reaction Conditions

Reaction Steps

tert-Butyl 3-carbamoylpiperazine-1-carboxylate (340 mg, 1.48 mmol) was dissolved in methanol (10 mL) and cooled to 0° C. To the reaction mixture were added 35% formaline solution (185 mg) followed by sodium triacetoxyborohydride (0.95 g, 4.48 mmol). The reaction mixture was allowed to warm up to room temperature and further stirred for 4 h. The reaction mixture was quenched with 10% NaHCO3 solution. The reaction mixture was diluted with EtOAc and the organic layer was separated in separatory funnel. The organic layer was dried over anhydrous Na2SO4 and concentrated in reduced pressure to afford tert-butyl 3-carbamoyl-4-methylpiperazine-1-carboxylate (310 mg, yield 86%). 1H NMR (300 MHz, CDCl3) δ 6.51 (br s, 1H), 5.47 (br s, 1H), 4.21-4.15 (m, 1H), 4.03-3.97 (m, 1H), 2.93-2.81 (m, 3H), 2.64-2.59 (dd, J=10.6 Hz, 3.8 Hz, 1H), 2.31 (s, 3H), 2.24-2.19 (td, J=11.7 Hz, 3.3 Hz, 1H), 1.46 (s, 9H). MS (ESI) m/z: Calculated for C11H21N3O3: 243.16. found: 244.3 (M+H)+

Provenance & Evidence