N-bromobutanimide → tert-Butyl 2-bromo-6,7-dihydrothieno[3,2-c]pyridine-5(4H)-carboxylate
Reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][C:11]2[S:14][CH:15]=[CH:16][C:10]=2[CH2:9]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].C1C(=O)N([Br:24])C(=O)C1>C(#N)C>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][C:11]2[S:14][C:15]([Br:24])=[CH:16][C:10]=2[CH2:9]1)=[O:7])([CH3:4])([CH3:2])[CH3:3]Participants
4
Procedure
To a solution of 6,7-dihydro-4H-thieno[3,2-c]pyridine-5-carboxylic acid tert-butyl ester (240 mg, 1.0 mmol) in acetonitrile (5 ml) cooled to 0° C. is added NBS (183 mg, 1.03 mmol, 1.03 eq.). The mixture is stirred at rt overnight. The organic phase is collected, washed with water (10 ml) and brine (10 ml), dried over sodium sulfate, and concentrated. The residue is purified by silica gel chromatography (hexane/EtOAc 10:1) to give the title compound. MS (+VE) m/z 318.1 (M++1).