Cyclic sulphur-nitrogen compounds and phosphorus reagents: Part IV1-Reactions of phosphiniminocyclotrisulphurtrinitride, (R) Ph2PN-S3N3 (R = Phenyl- and morpholino-) with Ph3P and (OC4H8N) Ph2P: six-membered to eight-membered ring (6→8) conversions

Abstract

Triphenylphosphine (A) reacts slowly with Ph₃PN-S₃N₃(I) both in CH₃CN and C₆H₆ to produce the known disubstituted eight-membered heterocycle, 1,5-(Ph₃PN)₂S₄N₄(III). The recently reported 1,5-[(OC₄H₈N)Ph₂PN]₂S₄N₄ (IV) is obtained in better yield (ca. 70%) from the reaction between (OC₄H₈N)Ph₂PN-S₃N₃(II) and (OC₄H₈N)Ph₂P(B) in acetonitrile. However, reactions in benzene of (I) with (OC₄H₈N)Ph₂P and of (II) with Ph₃P afford an inseparable mixture of (III) and (IV). Reaction temperature appears to be critical in the e ring transformation reactions.