[N:1]1[CH:6]=[CH:5][C:4]([CH2:7][C:8]([O:10][CH2:11][CH3:12])=[O:9])=[CH:3][CH:2]=1.[CH3:13][S:14][C:15](SC)=[C:16]([C:19]#[N:20])[C:17]#[N:18].O1CCOCC1.[H-].[Na+]>C(O)(=O)C>[C:17]([C:16]([C:19]#[N:20])=[C:15]([C:2]1[CH:3]=[C:4]([CH2:7][C:8]([O:10][CH2:11][CH3:12])=[O:9])[CH:5]=[CH:6][N:1]=1)[S:14][CH3:13])#[N:18]To a mixture of ethyl 4-pyridylacetate (46.7 g, 0.28 mol), 3,3-bis(methylthio)-2-cyanoacrylonitrile (47.6 g, 0.28 mol) and p-dioxane (300 ml) cooled in an ice bath was added 60% NaH (11.2 g, 0.28 mol) over 30 minutes. The mixture was slowly warmed to room temperature over 2 hours and was stirred at ambient temperature for 4 hours. The mixture was poured into ice-water, acidified with acetic acid and the resulting precipitate was collected by filtration and washed with water. The product was recrystallized from cyclohexane and dried at 70°-75° C. in high vacuum to afford 40.3 g (50%) of ethyl 2-(2,2-dicyano-1-methylthioethenyl)-4-pyridylacetate as orange crystals, m.p. 148°-152° C.
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