SYNTHESIS OF 8-SUBSTITUTED-16H-DINAPHTHO [2,1-d:1′,2′-g] 1, 3, 2-DIOXAPHOSPHOCIN 8-OXIDES

A new family of phosphorus heterocycles, namely 8-substituted-16H-dinaphtho[2, 1-d: 1′,2′-g]1, 3, 2- dioxaphosphocin 8-oxides, has been obtained via a synthesis from reaction of bis(2-hydroxy-1-naphthyl)methane with a series of aryl phosphorodichloridates in dry benzene in the presence of triethylamine. NMR analysis of a solution of the title compounds revealed essentially no coupling between the bridged methylene protons and the P atom which suggested the dioxaphosphocin ring may exist in a boat conformation in solution. An X-ray diffraction analysis of a crystal of 8-(2′,3′-dimethylphenoxy)- 16H-dinaphtho[2,1-d:1′,2′-g]1,3,2-dioxaphosphocin 8-oxide does indicate that in the solid state the dioxaphosphocin ring is in a distorted and extended boat-like conformation with the P[dbnd]O and bridged CH2 groups directed away from each other. Electron impact mass spectral analysis confirmed the structures of the esters and showed M+, (M — R)+, and (M – OR)+ ions containing the dioxaphosphocin ring system.