N-bromobutanimide → HCID 54415983, compound

HRID 1439921Notes

Reaction equation

[CH3:1][O:2][C:3]([C:5]1[NH:6][C:7]2[C:12]([CH:13]=1)=[C:11]([CH2:14][CH2:15][CH:16]=[CH:17][C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[CH:10]=[C:9]([Cl:25])[CH:8]=2)=[O:4].C1C(=O)N([Br:33])C(=O)C1>CN(C=O)C.C([O-])(O)=O.[Na+]>[CH3:1][O:2][C:3]([C:5]1[NH:6][C:7]2[C:12]([C:13]=1[Br:33])=[C:11]([CH2:14][CH2:15][CH:16]=[CH:17][C:18]([O:20][C:21]([CH3:22])([CH3:24])[CH3:23])=[O:19])[CH:10]=[C:9]([Cl:25])[CH:8]=2)=[O:4]

Participants

Conditions

Temperature: 0 °C

Procedure

To a solution of 6-chloro-4-(4-tert-butoxycarbonyl-3-butenyl)indole-2-carboxylic acid methyl ester (12.0 g, 33 mmol) in DMF (120 mL) was added slowly a solution of NBS (5.87 g, 33 mmol) in DMF (60 mL) at 0° C. The mixture was stirred for 1 h at 0° C., diluted with aqueous NaHCO3, and extracted with 2:1 ethyl acetate/toluene. The extract was washed with water and brine, dried over MgSO4, and concentrated. The residue was purified by silica gel column chromatography with 8:1 to 5:1 hexane/ethyl acetate to give 13.3 g of the title compound (91%): 1H NMR (CDCl3) δ9.15 (bs, 1H), 7.28 (d, 1H, J=1.8 Hz), 6.97 (dt, 1H, J=15.8, 6.9 Hz), 6.93 (d, 1H, J=1.8 Hz), 5.83 (dt, 1H, J=15.8, 1.7 Hz), 3.99 (s, 3H), 3.32 (dd, 2H, J=8.3, 7.9 Hz), 2.57 (m, 2H), 1.50 (s, 9H).

Workup

extractionextracted with 2:1 ethyl acetate/toluene
washThe extract was washed with water and brine
dry with materialdried over MgSO4
concentrationconcentrated
customThe residue was purified by silica gel column chromatography with 8:1 to 5:1 hexane/ethyl acetate

Sources & evidence

ORD record: ord-b7e65275ab824423acbf9b1ef6a66709
Source dataset: uspto-grants-1996_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05496843

Reaction notes

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