Abstract
The title compound, C26H22N5O4P3·C3H6O, has been achieved in a two-step synthesis that does not require chromatography. This mol-ecule contains a seven-membered spiro-cyclic ring at two P-atom positions and a five-membered ring containing new P-N bonds at the other P-atom position. Endocyclic torsion angles about the central biphenyl C-C bonds are -41.5 (3) and -44.4 (3)°, and P-N bonds of the central P3N3 ring are within the range 1.5665 (17)-1.6171 (17) Å, while the P-O distances are in the range 1.5940 (14)-1.6041 (14) Å. One N-H group makes an inter-molecular N-H⋯N hydrogen bond, forming centrosymmetric dimers, while the other N-H group makes an N-H⋯O hydrogen bond to the acetone solvent mol-ecule. The crystal was a two-component non-merohedral twin with ratio 0.811/0.189.