N-bromobutanimide → tert-Butyl ((5-bromothiophen-2-yl)methyl)carbamate

HRID 1484909Notes

Reaction equation

HRID 1484909 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH2:6][NH:7][C:8](=[O:14])[O:9][C:10]([CH3:13])([CH3:12])[CH3:11].C1C(=O)N([Br:22])C(=O)C1>CN(C=O)C.C(OCC)(=O)C>[Br:22][C:5]1[S:1][C:2]([CH2:6][NH:7][C:8](=[O:14])[O:9][C:10]([CH3:11])([CH3:13])[CH3:12])=[CH:3][CH:4]=1

Participants

5

Reactant 2

HCID 67184N-bromobutanimideHCID 4935536Thiophen-2-ylmethyl-carbamic acid tert-butyl ester

Product 1

HCID 2779810tert-Butyl ((5-bromothiophen-2-yl)methyl)carbamateYield 91.3%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
20 °C

Procedure

To a solution of produce tert-butyl thiophen-2-ylmethylcarbamate (1.28 g, 6 mmol, 1.0 equiv.) in DMF (4 mL) was added NBS (1.17 g, 6.6 mmol, 1.1 eq). After stirring at 20° C. for 5 h, the reaction mixture was diluted with ethyl acetate and washed with water for three times. The organic layer was dried (MgSO4) and concentrated in vacua. The residue was purified by silica gel column chromatography (PE/EtOAc=100:1 to 5:1) to afford tert-butyl (5-bromothiophen-2-yl)methylcarbamate (1.6 g, 91%). LC-MS (m/z)=235.9 [M−55]+. 1H NMR (400 MHz, DMSO-d6): δ 1.39 (s, 9H), 4.20 (d, J=6.0 Hz, 2H), 6.76 (d, J=4.0 Hz, 1H), 7.03 (d, J=3.6 Hz, 1H), 7.52 (t, J=5.6 Hz, 1H).

Workup

  1. washwashed with water for three times
  2. dry with materialThe organic layer was dried (MgSO4)
  3. concentrationconcentrated in vacua
  4. customThe residue was purified by silica gel column chromatography (PE/EtOAc=100:1 to 5:1)

Sources & evidence

ORD record
ord-2a441d7b9e434ca6a6e555964b42517c
Source dataset
uspto-grants-2016_08
Patent number
US09422271B2

Reaction notes

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