COMPOUNDS WITH 1,3-DIMETHYL-1,3-DIAZA-2-PHOSPHETIDINE-4-THIONE FRAMEWORK

Compounds involving the 1,3-dimethyl-1,3-diaza-2-phosphetidin-4-thione framework: Synthesis of 1,3-dimethyl-1,3-diaza-2lambda3-phosphetidin-4-thione derivatives and oxidation reactions at the phosphorus(III) atom. The reactions of singly lithiated N,N'-dimethylthiourea 1 with diorganoaminodichlorophosphines (organo groups: CH2CH=CH2 2, C6H11 3, Ph 4) are described. The resulting 1,3-dimethyl-1,3-diaza-2lambda3-phosphetidin-4-thione derivatives 5-7 undergo oxidation reactions with trimethylsilyl azide, hexafluoroacetone, tetrachloroorthobenzoquinone and elemental sulfur. With trimethylsilyl azide and hexafluoroacetone a rearrangement of the four-membered diazaphosphetidine ring system was observed in addition to the oxidation at the phosphorus atom. The new compounds 5, 7, 9, 11 and 13-19 were characterized by elemental analysis, H-1-, C-13-, P-31-NMR-spectroscopy and mass spectrometry; 6, 10 and 18 were characterized by X-ray structure analysis. Compound 6 displays two independent molecules with no significant differences; the P-N bond lengths are correlated with the pyramidality of the nitrogen atoms. Tle phosphorus atom is pyramidally coordinated. The phosphorus atom of compound 10 is tetrahedrally coordinated; the configuration at the double bond Cl=N3 is E. Compound 18 possesses crystallographic mirror symmetry; the geometry at the phosphorus atom is square pyramidal. In all the structures the N-P-N angle in the four-membered ring necessarily departs considerably from ideal values.