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

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence