2-Furanmethanethiol → 2,3-dimethyl-4-(2-furylmethylthio)pyridine N-oxide

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Reaction Steps

6 g of (60%) NaOH are added in portions to 50 ml of dry dioxane, the mixture is stirred for 15 minutes, 11.7 g (0.11 mol) of 2-furylmethylmercaptan are metered in, in the course of 20 minutes, and the mixture is again stirred for 30 minutes until the evolution of gas has ceased. A solution of 14.4 g (0.1 mol) of 4-chloro-2,3-dimethylpyridine N-oxide in 100 ml of dioxane is subsequently added dropwise in the course of 20 minutes, the reaction mixture is stirred at RT for 1 h, subsequently at 70° C. for 1 h and thereupon at 100° C. for a further 1 h. After the reaction has ended, the mixture is allowed to cool, diluted with 500 ml of water and extracted 4 times using in each case 300 ml of ethyl acetate. The combined organic phases are washed with water, dried over magnesium sulfate, concentrated and crystallized by adding diisopropyl ether. This gives 18.8 g (80% of theory) of 2,3-dimethyl-4-(2-furylmethylthio)pyridine N-oxide of m.p. 111°-112° C.

Provenance & Evidence