Experimental

disorder in main residue; R factor = 0.027; wR factor = 0.081; data-to-parameter ratio = 29.9. The P atom in the title compound, C15H18NO3P, is in a distorted tetrahedral P(O)(O)2N environment; the bond angles at P are in the range 98.16 (6)–115.82 (6). In the crystal, adjacent molecules are linked via N—H O P hydrogen bonds into a chain running parallel to the b axis. The methyl groups are disordered over two sets of sites in a 0.677 (14):0.323 (14) ratio. The crystal studied was a non-merohedral twin with a refined minor component of 22.31 (4)%. Related literature For bond lengths and angles in a related structure, see: Sabbaghi et al. (2011)