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

HRID 874967Notes

Reaction equation

[C:1]([CH:4]1[NH:9][CH2:8][CH2:7][N:6]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:5]1)(=[O:3])[NH2:2].C=O.[C:19](O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>CO>[C:1]([CH:4]1[N:9]([CH3:19])[CH2:8][CH2:7][N:6]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:5]1)(=[O:3])[NH2:2]

Participants

Conditions

Temperature: 0 °C

Procedure

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)+

Workup

temperatureto warm up to room temperature
customThe reaction mixture was quenched with 10% NaHCO3 solution
additionThe reaction mixture was diluted with EtOAc
customthe organic layer was separated in separatory funnel
dry with materialThe organic layer was dried over anhydrous Na2SO4
concentrationconcentrated in reduced pressure

Sources & evidence

ORD record: ord-848205728a0b4f09b22f3a26c1328d7d
Source dataset: uspto-grants-2015_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08981084B2

Reaction notes

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