Phosphonitrilic Compounds. II. Reactions of Phosphonitrilic Chlorides with Catechol and Triethylamine

Phosphonitrilic chloride trimer undergoes dehydrochlorination reactions with catechol and triethylamine to form tris(o-phenylenedioxy)phosphonitrile trimer and polymers. An unusual side reaction, involving phosphorus-nitrogen ring cleavage, yields the triethylamine salt of 2-(o-hydroxyphenoxy)-2,2'-spirobi[l,3,2-benzo-dioxaphosphole], which appears to exist as the hexavalent phosphorus anion tautomer in the crystalline state. This product was also formed when phosphonitrilic chloride tetramer or polymer was treated with catechol and triethylamine. The results are interpreted in terms of possible reaction mechanisms.