New syntheses of thionitrites and their chemical reactivites

Abstract

Both aryl and alkyl thionitrites (RSNO) were prepared quantitatively by the reaction of thiols with dinitrogen tetraoxide (N₂O₄) under mild conditions. Unstable thionitrites were identified by i.r. or u.v. spectra at low temperatures (e.g. 0 °C) or by their further reactions with nucleophiles leading to known derivatives. The spectroscopic data of these thionitrites are summarized and the highly reactive thionitrites were found to react readily with other nucleophiles such as thiols, sulphinic acids, alcohols, and secondary amines at ca.–5 °C. Treatment of thionitrites with other thiols or sulphinic acids was found to yield the corresponding unsymmetrical disulphides or thiolsulphonates in good yields. Similar treatment of thionitrites with secondary amines or alcohols gave the corresponding N-nitrosoamines, or disulphides and nitrites.