Phosphorus oxychloride → 2H-1,2,4,6-Thiatriazine, 3-chloro-2-ethyl-5-methoxy-, 1,1-dioxide

Participants

Reaction Steps

154 parts of phosphorus pentachloride were added, in the course of 2 minutes, to a stirred mixture of 128 parts of 6-ethyl-3-methoxy-6H-1,2,4,6-thiatriazin-5-one-1,1-dioxide and 840 parts of phosphorus oxychloride at 25° C. The reaction mixture was then stirred for 51/2 hours under reflux, after which it was evaporated down under reduced pressure. The oil which remained was taken up in 300 parts of 1,2-dichloroethane and the solution was chromatographed over neutral alumina (Activity I). After evaporating down, 127.5 parts (91% of theory) of 5-chloro-6-ethyl-3-methoxy-6H-1,2,4,6-thiatriazine-1,1-dioxide, of melting point 63°-70° C., were obtained (Compound No. 2).

Provenance & Evidence