Phosphorus pentachloride → 2,7-Dichlorobenzo[d]oxazole

Participants

Reaction Steps

A mixture of 7-chloro-2-mercaptobenzoxazole (14.8 g.) and phosphorus pentachloride (29.2 g.) was heated at 160°-170° under reflux for 3 hours. The flask was fitted with a distilling head and the product was distilled in vacuo. The first two fractions were unreacted phosphorus chloride. Afterwards, the product distilled to give 2,7-dichlorobenzoxazole. This compound was reacted with hydrazine using the method described in procedure (a) of Example 1 and then reacted with acrylonitrile using procedure (c) of Example 1 to give 3-[1-(7-chloro-2-benzoxazolyl)hydrazino]propanenitrile, m.p. 114°-115° C.

Provenance & Evidence