Reaction of phenylenedioxytrihalophosphoranes with arylacetylenes: II. Synthesis and steric structure of 6,7-dihalo-2-hydroxy-2-oxo-4-phenylbenzo[e]-1,2 lambda(5)-oxaphosphorin-3-enes

High-resolution mass spectrometry and NMR and IR spectroscopy were used to show that the products of reaction of 2,2,2,5-tetrachlorobenzo[d]-1,3,2 lam bda (5)-dioxaphosphole and 5-bromo-2,2,2-trichlorobenzo[d]-1,3,2 lambda (5) -dioxaphosphole with phenyl- and para-bromophenylacetylenes are trihalogena ted six-membered heterocycles, 2,6,7-trichloro-2-oxo-4-phenylbenzo[e]- and 4-aryl-7-bromo-2,6-dichloro-2-oxobenzo[e]-1,2 lambda (5)- oxaphosphorin-3-e nes. The steric structure of the 2-hydroxy derivatives formed by hydrolysis of the latter was studied by X-ray diffraction.