Reaction of trihalo(phenylenedioxy)phosphoranes with acetylenes: X. specific features of the reactions of substituted 2,2,2-trichloro-1,3,2λ5-benzodioxaphospholes with 3-chloro(bromo, iodo)propynes

It was shown for the first time that 3-chloro-, 3-bromo-, and 3-iodopropynes can react with 2,2,2-trichloro-, 2,2,2-trichloro-5-methyl-, and 5,6-dibromo-2,2,2-trichloro-1,3,2λ⁵-benzodioxaphospholes to give derivatives of 4-(halomethyl)-2-chloro-2H-1,2λ⁵-benzoxaphosphinin-2-ones. The reaction involves nonselective chlorination of the phenylene substituent in different positions, and the resulting isomer ratio is temperature-dependent. In the reactions of 3-bromo-and 3-iodopropynes with 2,2,2-trichloro-1,3,2λ⁵-benzo-dioxaphosphole, a side process takes place, viz. nucleophilic substitution of bromine and iodine with chlorine. The structure of some of the prepared 4-(chloromethyl)-1,2-benzoxaphosphinines was studied by means of X-ray diffraction.