CHEMISTRY OF THE 1,3,5-TRIAZA-2-PHOSPHORIN-4,6-DIONES .12. SYNTHESIS AND CHARACTERIZATION OF TRIMETHYL-1,3,5-TRIAZA-4,6-DIONE-2-PHOSPHORINONIUM SALTS

The reaction of 1,5-bis(trimethylsilyl)-1,3,5-trimethylbiuret (1) with p-tolylsulfenyl chloride (2) furnished -tolyithio)-5-trimethylsilyl-1 ,3,5-trimethylbiuret (3). In the reaction of 3 with phenyldichlorophos phine, trimethyl-1,3,5-triaza-4,6-dione-2-phosphorinonium chloride (4) was formed. The same product was obtained from the reaction of 2-phen yl-1,3,5-trimethyl-1,3,5-triaza-2 lambda(3)-phosphorin-4,6-dione (6) w ith p-tolylsulfenyl chloride (2). Compound 4 was isolated and characte rized in the form of the hexachloroantimonate (4a). The spirophosphora ne ethyl-1,3,5-triaza-7,10-dioxa-8,9-perchlorobenzo-2 lambda(5)-phosph aspiro-[4.5]decan-4.6-dione (7) was prepared by the reaction of 4 with tetrachloroorthobenzoquinone. The new products were characterized by H-1- and C-13 NMR spectroscopy elemental analysis, P-31 NMR spectrosco py in the case of 4a, 6 and 7, and mass spectrometry (4a). Single-crys tal X-ray structural analyses of compounds 4a and 7 were conducted. Th e phosphorus atom of 4a has the expected tetrahedral geometry, with a rather short P-S bond of 204.9(2) pm. In 7 the geometry at phosphorus is almost ideal trigonal bipyramidal. Weak hydrogen bonds are formed f rom a C(:O) group to deuterochloroform of solvation.