Cyclic organophosphorus compounds: XVII—the mass spectra of some 5,5‐dimethyl‐perhydro‐1,3,2‐oxazaphosph(v)orines

Abstract

AbstractThe electron impact mass spectra of six 5,5‐dimethyl and eleven 3,5,5‐trimethyl‐perhydro‐1,3,2‐oxazaphosphorine 2‐oxides and 2‐sulphides are reported and compared with those of analogous 5,5‐dimethyl‐1,3,2‐dioxaphosph(v) orinans. Compounds of the 3,5,5‐trimethyl series produce an important ion at m/z 44 which clearly distinguishes them from the 5,5‐dimethyl series. The 2‐sulphides are characterized by loss of thiol radical rather than of sulphur; in the case of 2‐cyclohexylamino‐3,5,5‐trimethyl‐perhydro‐1,3,2‐oxazaphosphorine 2‐sulphide at least, the thiol hydrogen is derived from the oxazaphosphorine ring NCH2 group. Fission of the oxazaphosphorine ring occurs largely, but apparently not exclusively, at the POC linkages.