[Cl:1][C:2]1[C:7]([C:8]([OH:10])=[O:9])=[C:6]([C:11]([F:14])([F:13])[F:12])[N:5]=[CH:4][CH:3]=1.[N+](=[CH2:17])=[N-].N(N(C)C(N)=O)=O.C(O)(=O)C>C(OCC)(=O)C.C(OCC)C>[Cl:1][C:2]1[C:7]([C:8]([O:10][CH3:17])=[O:9])=[C:6]([C:11]([F:14])([F:12])[F:13])[N:5]=[CH:4][CH:3]=1To a stirred solution of 4-chloro-2-(trifluoromethyl)nicotinic acid (8.75 g, 38.8 mmol) in ethyl acetate (100 mL) in an ice bath is added a solution of diazomethane [generated from 12 g (116 mmol) of N-nitroso-N-methylurea] in diethyl ether (200 mL). The solution is stirred for 15 minutes, followed by the addition of acetic acid (until effervescence stops). The solution is concentrated in vacuo to afford 9.75 g (99%) of the title compound as a brown oil: 1H NMR (400 MHz, CD3OD), 8.686 (d, 1H), 7.828 (d, 1H), 3.937 (s, 3H). LC/MS (M+1)=240.1
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