N-bromobutanimide → HCID 58124920, compound

Reaction equation

[C:1]([N:5]1[CH2:29][CH2:28][CH2:27][CH2:26][C:8]2[CH:9]=[C:10]3[C:19]4[CH:18]=[C:17]([S:20]([CH2:22][CH3:23])=[O:21])[C:16]([O:24][CH3:25])=[CH:15][C:14]=4[CH2:13][CH2:12][N:11]3[C:7]=2[C:6]1=[O:30])([CH3:4])([CH3:3])[CH3:2].C1C(=O)N([Br:38])C(=O)C1>CN(C=O)C.O>[C:1]([N:5]1[CH2:29][CH2:28][CH2:27][CH2:26][C:8]2[C:9]([Br:38])=[C:10]3[C:19]4[CH:18]=[C:17]([S:20]([CH2:22][CH3:23])=[O:21])[C:16]([O:24][CH3:25])=[CH:15][C:14]=4[CH2:13][CH2:12][N:11]3[C:7]=2[C:6]1=[O:30])([CH3:2])([CH3:3])[CH3:4]

Participants

Procedure

A solution of 350 mg of 23c in 4 ml of DMF was treated with 155 mg of NBS. After stirring for 10 min. the reaction was diluted with 25 ml of water and extracted with ethyl acetate. The organic extract was washed with water, dried and concentrated, and the residue was treated with diisopropyl ether, to give 360 mg of 23d, Mp: 140-145° C. Rf 0.18 (heptane/ethyl acetate 1/1). LC-MS-ESI: [M+1] 506.97 and 524.99. NMR (CDCl3) δ 1.24 (t, 3, ethyl), 2.82 and 3.08 (2×m, 2, ethyl), 3.88 (s, 3, OCH3), 6.77, 8.78 (2×s, 2, Ar—H).