3-(6-Methyl-2-pyrid-yl)-2-phen-oxy-3,4-dihydro-1,3,2-benzoxaza-phosphirine 2-oxide.

In the title compound, C(19)H(17)N(2)O(3)P, the six-membered 1,3,2-oxaza-phospho-rine ring adopts a twist-boat conformation with the phosphoryl O atom in an equatorial position. The P=O(oxide) bond length is 1.457†(1)†à and the average value of the P-O distances is 1.588†à . The crystal structure is stabilized by C-H⋯O and C-H⋯π inter-actions.