N-bromobutanimide → ethyl 2-bromo-5,6-dihydro-4H-thieno[2,3-c]azepine-7(8H)-carboxylate
Reaction equation
[S:1]1[C:5]2[CH2:6][N:7]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH2:8][CH2:9][CH2:10][C:4]=2[CH:3]=[CH:2]1.C1C(=O)N([Br:23])C(=O)C1>C(#N)C>[Br:23][C:2]1[S:1][C:5]2[CH2:6][N:7]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH2:8][CH2:9][CH2:10][C:4]=2[CH:3]=1Participants
4
Procedure
To a solution of Compound 1044 (1.78 g, 7.90 mmol) in acetonitrile (80 mL) at 0° C. was slowly added NBS (1.69 g, 9.48 mmol). The reaction was stirred at room temperature for 30 minutes, at which point HPLC analysis indicated disappearance of starting material. The reaction was quenched by addition of saturated sodium bicarbonate (50 mL) and stirred for one hour. The reaction was then extracted with diethyl ether (3×100 mL), the organics concentrated, and the residue purified by silica chromatography (5-30% ethyl acetate in hexanes) to give ethyl 2-bromo-5,6-dihydro-4H-thieno[2,3-c]azepine-7(8H)-carboxylate as a pale yellow oil (Compound 1045, 2.07 g, 86% yield); 1H NMR (300 MHz, CDCl3): δ 6.67 (s, 1H), 4.38 (s, 2H), 4.15-3.99 (m, 4H), 3.64 (d, J=3.8 Hz, 2H), 2.73-2.67 (m, 2H) and 1.22-1.09 (m, 3H).