Diethyl Ether → 5-Chloro-2-isothiocyanatopyridine

Participants

Reaction Steps

A solution of 16.3 ml. of thiophosgene in 600 ml. of ether is added with rapid stirring to a suspension of 25.6 g. of 5-chloro-2-aminopyridine and 42 g. of calcium carbonate in 600 ml. of water. The reaction mixture is stirred for 11/2 hours and the ether layer separated and the water layer extracted with a 400 ml. portion of ether. The combined ether extracts are washed with water, dried over magnesium sulfate and evaporated to dryness in vacuo affording 29.9 g. of a dark red oil. The oil is distilled at 0.75 mm. of Hg. at a temperature 96° C. affording 5-chloro-2-pyridylisothiocyanate.

Provenance & Evidence