[Cl:1][C:2]1[C:7]([CH:8](O)[CH2:9][N+:10]([O-:12])=[O:11])=[CH:6][CH:5]=[C:4]([C:14]([F:17])([F:16])[F:15])[N:3]=1.C(OC(=O)C)(=O)C>ClCCl.CN(C)C1C=CN=CC=1>[Cl:1][C:2]1[C:7](/[CH:8]=[CH:9]/[N+:10]([O-:12])=[O:11])=[CH:6][CH:5]=[C:4]([C:14]([F:15])([F:16])[F:17])[N:3]=1To a stirred solution of 1-[2-chloro-6-(trifluoromethyl)pyridin-3-yl]-2-nitroethanol (Int-18) (27 g, 1.0 eq.) in dichloromethane (270 mL) was added 4-dimethylamino pyridine (13.5 g, 1.1 eq.) followed by drop wise addition of acetic anhydride (13.5 g, 1.3 eq) at 0° C. and stirred for 15 min. The progress of the reaction was monitored by TLC. After completion of reaction, the reaction mixture was quenched with ice water and extracted with dichloromethane (2×200 mL). The combined organic layer was washed with water (200 mL), brine (200 mL), dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure to get crude 2-chloro-3-[(E)-2-nitrovinyl]-6-(trifluoromethyl)pyridine (Int-19) (22.0 g, 87.6%).
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