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To a stirred solution of 2,3-dichloro-5-methylthiomethylpyridine (3.5 g, 16.8 mmol) and cyanamide (1.43 g, 34 mmol) cooled in an ice-water bath was added iodobenzenediacetate (6.76 g, 21 mmol) in one portion. The resulting mixture was stirred at 0° C. for 30 min and then continued at room temperature for 1 h. A solution of sodium bisulfite (2 g) in water (50 mL) was added and the organic phase separated. The aqueous phase was extracted with dichloromethane (2×50 mL). The combined organic phase was dried over MgSO4 and the solvent evaporated to give a dark red oily residue which was triturated with boiling ether (2×40 mL) with the ether being discarded each time. After standing at room temperature overnight, the residue solidified, which was triturated with hot ethyl acetate (25 mL). Upon cooling down, the off-white solid product was collected by filtration and dried. Concentration of the filtrate and repeating the trituration process gave additional product. The total yield for the product [1-(5,6-dichloropyridin-3-yl)methyl]-λ4-sulfanylidenecyanamide was 2.45 g (58.8%). LC-MS: calcd for C8H7Cl2N3S [M]+ 247. Found 247.

1. waitcontinued at room temperature for 1 h
2. customthe organic phase separated
3. extractionThe aqueous phase was extracted with dichloromethane (2×50 mL)
4. dry with materialThe combined organic phase was dried over MgSO4
5. customthe solvent evaporated
6. customto give a dark red oily residue which
7. customwas triturated with boiling ether (2×40 mL) with the ether being
8. waitAfter standing at room temperature overnight
9. customthe residue solidified, which was triturated with hot ethyl acetate (25 mL)
10. temperatureUpon cooling down
11. filtrationthe off-white solid product was collected by filtration
12. customdried
13. customgave additional product