[4-CHLOROPENTAFLUORO-1,3-BUTADIENE(2] CYCLOADDITIONS OF HALOGENO THIAZYLS WITH 2)

Reactions of (XSN)n (n = 3, 1; X = Cl, F) with 2-chloropentafluoro-1,3 -butadiene provide the 1lambda4,2-thiazines 1a and 1b. Fluorination wi th KF converts 1a in 88% yield to 1b. CH3OH reacts with 1b to form the 1-methoxy derivative 1c. The structure of 1c was determined by single -crystal X-ray diffraction analysis. With water 1a forms the 1,2-thiaz in-3-one 1-oxide 2.