A method of phosphorylation of heterocycles incorporating 1,3-azole moiety
with phosphorus(III) halides is elaborated. As a result, previously unknown
azolyldihalogenphosphines are prepared. Influence of heteroatom and quanti
ty of nitrogen atoms in a cycle on the activity of azoles is studied. React
ion of 5-aminopyrazole derivatives with phosphorus(III) halides affords nov
el phosphorus-containing bi- and tricyclic fused systems.