Studies on the Synthesis of Phosphorus Heterocycles I. Thiazaphosphorinobenzodiazaphosphorine 12-Oxides

Article abstract of DOI:10.1055/s-1989-27336

N-Substituted isatoic anhydrides 4 react with 2-bromoethylamino hydrobromide in the presence of triethylamine to form oxazolines 6, which are treated with phosphorus trichloride to give a key intermediate 7.Reaction of 7 with phenyl isothiocyanate yields fused phosphorus heterocycles 9.Several methods for preparing compounds 9 and the mechanism of cyclization are discussed.