[Cl:1][C:2]1[CH:3]=[N:4][C:5]([CH3:11])=[C:6]([CH:10]=1)[C:7](O)=[O:8].C(Cl)[Cl:13].C(Cl)(=O)C(Cl)=O>CN(C=O)C>[Cl:1][C:2]1[CH:3]=[N:4][C:5]([CH3:11])=[C:6]([CH:10]=1)[C:7]([Cl:13])=[O:8]5-Chloro-2-methyl-nicotinic acid (4.15 g, 24.2 mmol) is placed in a flask with DCM (100 mL) and oxalyl chloride (3.68 g, 29 mmol). DMF (200 μL) is added and the reaction mixture is stirred at r.t. for 1 hour (gas evolution). The mixture is filtered and the solvent is removed in vacuo to afford the title product which is used in the next step without further purification.
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