[CH2:1]([O:8][C:9]1[N:24]=[CH:23][C:22]([OH:25])=[C:21]([O:26][CH2:27][C:28]2[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=2)[C:10]=1[C:11]([O:13][CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)=[O:12])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C1C(=O)N([Br:41])C(=O)C1.O>CN(C=O)C>[CH2:1]([O:8][C:9]1[N:24]=[C:23]([Br:41])[C:22]([OH:25])=[C:21]([O:26][CH2:27][C:28]2[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=2)[C:10]=1[C:11]([O:13][CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)=[O:12])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1A mixture of benzyl 2,4-bis(benzyloxy)-5-hydroxynicotinate (0.29 g, 0.66 mmol) and NBS (0.13 g, 0.72 mmol) in DMF (1.2 mL) was stirred at room temperature for 5 min then treated with water. The mixture was extracted with ethyl acetate. The organic layers were combined and washed with brine, dried over sodium sulfate, evaporated and purified by silica chromatography (0-30% ethyl acetate in hexanes) to give benzyl 2,4-bis(benzyloxy)-6-bromo-5-hydroxynicotinate (0.23 g, 68%).
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