Reaction of 4,6-bis(tert-butyl)-2,2,2-trichlorobenzo[d]-1,3,2-dioxaphosphole with phenylacetylene. ipso-Substitution of the tert-butyl group

The reaction of 4,6-bis(tert-butyl) - 2,2,2 -trichlorobenzo[d] - 1, 3.2 -di oxaphosphole with phenylacetylene follows the mechanism of ipso-substitutio n of the tert-butyl group that is in para-position relative to the endocycl ic O atom of the heterocycle, predominantly yielding 8-(tert-butyl)-2,6-dic hloro-2-oxo-4-phenylbenzo[e]-1,2-oxaphosphorinine (NMR data). The structure of its hydrolysis product, 8-(tert-butyl)-6-chloro-2-hydroxy-2-oxo-4-pheny lbenzo[e]-1,2-oxaphosphorinine, was proved by X-ray diffraction analysis.