Potassium Carbonate → Tert-butyl 3-methyl-4-[(5-nitro-1-benzofuran-7-yl)methyl]piperazine-1-carboxylate

HRID 1162052Notes

Reaction equation

Br[CH2:2][C:3]1[C:11]2[O:10][CH:9]=[CH:8][C:7]=2[CH:6]=[C:5]([N+:12]([O-:14])=[O:13])[CH:4]=1.C([O-])([O-])=O.[K+].[K+].[CH3:21][CH:22]1[NH:27][CH2:26][CH2:25][N:24]([C:28]([O:30][C:31]([CH3:34])([CH3:33])[CH3:32])=[O:29])[CH2:23]1>CC#N>[CH3:21][CH:22]1[N:27]([CH2:2][C:3]2[C:11]3[O:10][CH:9]=[CH:8][C:7]=3[CH:6]=[C:5]([N+:12]([O-:14])=[O:13])[CH:4]=2)[CH2:26][CH2:25][N:24]([C:28]([O:30][C:31]([CH3:32])([CH3:34])[CH3:33])=[O:29])[CH2:23]1

Participants

Conditions

Temperature: 80 °C

Procedure

A mixture of 7-(bromomethyl)-5-nitro-1-benzofuran (120 mg, 70 mol %, 0.39 mmol; Intermediate 64), K2CO3 (162 mg, 1.17 mmol) and tert-butyl 3-methylpiperazine-1-carboxylate (94 mg, 0.47 mmol) in dry MeCN (5 mL) was heated at 80° C. while stirring for 1 h 45 min using a StemBlock. The solvent was evaporated under reduced pressure and the residue was partitioned between water and DCM (×2). The organic layers were combined, dried (Na2SO4) and purified using flashtube (10% MeOH in DCM). This afforded the title product (115 mg, 78%) as a light yellow sticky oil. HPLC 99%, RT=2.47 min (System A; 5-60% MeCN over 3 min), 99%, RT=2.27 min (System B; 5-60% MeCN over 3 min). MS (ESI+) for C19H25N3O5 m/z 376 (M+H)+.

Workup

customThe solvent was evaporated under reduced pressure
customthe residue was partitioned between water and DCM (×2)
dry with materialdried (Na2SO4)
custompurified

Sources & evidence

ORD record: ord-47f5bb612cf841a9b9b3ca421d5a7d83
Source dataset: uspto-grants-2010_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07820675B2

Reaction notes

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