Reaction of methylhydrazine with dimethyl chlorothiophosphate

Abstract

The reaction of 2 equivalents of methylhydrazine with 1 equivalent of (MeO)₂P(S)Cl at 0 °C produced the phosphorus hydrazide (MeO)₂P(S)NMeNH₂1 in good yield. However, at 25 °C a mixture of three products was obtained according to ¹H and ³¹P NMR spectra. The pure individual components were separated by column chromatography. Proton and ³¹P NMR analysis revealed them to be 1, (MeO)₂P(S)(NMeNH)(S)P(OMe)₂2 and (MeO)₂P(S)NHNHMe 3. During the chromatographic separation of 1–3 another component was also eluted in 5–8% yield, ¹H, ³¹P NMR and FAB mass spectrometric analysis of which indicated it to be (MeO)₂P(S)(NMeNH)(O)P(OMe)Me4. New synthetic strategies to produce 2 in good yields are also described.