Water → tert-Butyl 4-(5-methyl-1,2,4-oxadiazol-3-yl)piperazine-1-carboxylate

HRID 1775320Notes

Reaction equation

[OH:1][NH:2][C:3]([N:5]1[CH2:10][CH2:9][N:8]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH2:7][CH2:6]1)=[NH:4].[C:18](OC(=O)C)(=O)[CH3:19].O>N1C=CC=CC=1>[CH3:18][C:19]1[O:1][N:2]=[C:3]([N:5]2[CH2:6][CH2:7][N:8]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH2:9][CH2:10]2)[N:4]=1

Participants

Conditions

Temperature: 80 °C

Procedure

To a solution of tert-butyl 4-(N-hydroxycarbamimidoyl)piperazine-1-carboxylate (771 mg, 3.16 mmol) in pyridine (8 mL) was added acetic anhydride (320 L, 3.42 mmol) and the reaction was heated to 80° C. for 3 h. The mixture was cooled to room temperature, poured into water and extracted with EtOAc. The organic layer was washed with water and brine, dried (Na2SO4) and concentrated under reduced pressure to yield 774 mg of a yellow solid. After purification by flash chromatography (silica, gradient of 0.5 to 3% methanol in dichloromethane) 509 mg of an off-white solid were obtained (1.897 mmol, 60%). MS (ESI) m/z=291.1 [M+Na]+.

Workup

temperatureThe mixture was cooled to room temperature
extractionextracted with EtOAc
washThe organic layer was washed with water and brine
dry with materialdried (Na2SO4)
concentrationconcentrated under reduced pressure

Sources & evidence

ORD record: ord-c4381c964faf4a398db4a678fee17190
Source dataset: uspto-grants-2016_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09260441B2

Reaction notes

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