[F:1][C:2]([F:13])([F:12])[C:3]([NH:10][CH3:11])=[CH:4][C:5]([O:7]CC)=O.[H-].[Na+].[N-:16]=[C:17]=[S:18].[C:19]1([CH3:25])[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1>CN(C)C=O>[CH3:11][N:10]1[C:3]([C:2]([F:1])([F:13])[F:12])=[CH:4][C:5](=[O:7])[N:16]([CH2:25][C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[C:17]1=[S:18]
4,4,4-Trifluoro-3-(methylamino)-2-butenoic acid, ethyl ester, (2Z)-(1.43 g) in toluene (25 ml) was slowly added to a stirred suspension of sodium hydride (60%, 0.28 g) in anhydrous N,N-dimethylformamide (25 ml) at −10° C. The solution was stirred for 0.5 hr at this temperature and cooled to −50° C. The above isothiocyanate dissolved in toluene (25 ml) was added drop wise with stirring to the solution, while maintaining the temperature at −50° C. The solution was then allowed to warm to −20° C. and stirred for 2 hr. After neutralization with dilute hydrochloric acid, the solution was partitioned between water and ethyl acetate and the organic layer was evaporated to furnish a crude product. Column chromatography over silica gel (eluent, hexane:ethyl acetate, 90:10) afforded the title compound (2.6 g). 1H NMR, CDCl3, 3.86 (3H, m), 5.74 (2H, s), 6.51 (1H, s), 7.27-7.30 (3H, m), 7.42-7.46 (2H, m).
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