OLIGOCYCLIC DERIVATIVES FROM THE PARTIAL BROMINATION OF 2-METHYL-5-PHENYL-1,2,4,3-TRIAZAPHOSPHOLE

With less than one mol Br, per mol of the 2-methyl-5-phenyl-1,2,4,3-tr iazaphosphole (1) an equilibrium mixture forms, which contains besides 1 and its dimeric dibromide 3 at least three more components (4, 5, 6 ), which are intermediate between 1 and 3. In 4, 5 and 6 two, three an d four triazaphosphole rings are connected to each other by PN bonds w ith the phosphorus atoms being in part tervalent, in part pentavalent. Secondary amines convert compounds 4 and 5 to the amino derivatives 1 1 and 12 of the same bi- and tricyclic structure. Of the bicyclic dime thylamino derivative 11b a number of reactions are reported which all selectively involve the tervalent phosphorus only: Oxidation by bromin e, elemental sulfur, phenyl azide and ethyl diazoacetate, insertion of CS2, RNCS and RNCO into the exocyclic PN bond and formation of chelat e complexes with PdCl2 and PtCl2. The same is shown by the reaction of the tricyclic piperidyl derivative 12c with elemental sulfur.