6-PHENOXY-3-PYRIDINYL ISOTHIOCYANATE synthesis

Yield:-

Reaction Conditions:

in 1,4-dioxane;(2S)-N-methyl-1-phenylpropan-2-amine hydrate;

Steps:

8 (Comp. 3.1)

EXAMPLE 8 Preparation of 2-phenoxy-5-isothio-cyanopyridine (Comp. 3.1) 18.6 g of crude 2-phenoxy-5-amino-pyridine, obtained by catalytic hydrogenation, is dissolved in 200 ml of dioxane. This solution is added dropwise at room temperature, in the course of 15 minutes, to a mixture of 12.5 g of thiophosgene in 200 ml of dioxane. The solution is further stirred overnight, and then stirred into 1 liter of ice water; the solution is neutralised with 2N NaOH, and the crystalline precipitate chromatographed through silica gel, with methylene chloride as the eluant. The resulting pure final productproduct melts at 42°-43° C.

References:

US4001254,1977,A