[Cl:1][C:2]1[N:17]=[CH:16][CH:15]=[C:14]([Cl:18])[C:3]=1[C:4]([O:6][CH2:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)=[O:5].[Li+].CC([N-]C(C)C)C.[I:27]I>C1COCC1>[Cl:1][C:2]1[N:17]=[CH:16][C:15]([I:27])=[C:14]([Cl:18])[C:3]=1[C:4]([O:6][CH2:7][C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1)=[O:5]Into a solution of benzyl 2,4-dichloronicotinate (4.35 g, 15.4 mmol) in THF (40 mL) at −78° C. was added LDA (1.5 M×11.8 mL, 17.7 mmol) dropwise. The mixture was stirred at −78° C. for 30 min. Iodine (4.7 g, 18.5 mmol) was added portionwise. The temperature was then allowed to rise to room temperature slowly and the reaction was quenched with saturated NH4Cl solution. 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 (0-7% ethyl acetate in hexanes) to give benzyl 2,4-dichloro-5-iodonicotinate (3.8 g, 60%).
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