Potassium Carbonate → O,O-dimethyl O-(3,5-dichloro-6-fluoro-2-pyridinyl) phosphorothioate

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Reaction Conditions

Reaction Steps

A mixture was prepared by admixing, with stirring, 20 grams (g) (0.11 mole (m)) of 3,5-dichloro-6-fluoro-2-pyridinol, 16 g (0.116 m) of potassium carbonate, 0.2 g of mercuric chloride and 250 milliliters (ml) of acetonitrile. To this mixture, with stirring, was added dropwise 16 g (0.1 m) of O,O-dimethyl phosphorochloridothioate. After the addition was complete, the mixture was stirred for an additional 0.5 hour and then heated to about 50° C., with stirring, for 2 hours. The reaction mixture was cooled to room temperature and filtered to remove insolubles. The solvent was removed by evaporation under reduced pressure. The residue was dissolved in 100 ml of benzene and washed with water. The organic layer was dried and filtered. The benzene was removed by evaporation. The residue (20 g of an oil) was crystallized from 30 ml of hexane to give 13 grams of O,O-dimethyl O-(3,5-dichloro-6-fluoro-2-pyridinyl) phosphorothioate. The product, a solid, melted at room temperature and had a refractive index of nd25 =1.5370. Upon analysis, the product was found to have carbon, hydrogen and nitrogen contents of 27.40, 2.28 and 4.27 percent, respectively, as compared with the theoretical contents of 27.46, 2.31 and 4.58 percent, respectively, as calculated for the above compound.

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