The mixed-amide phosphinates, rac-phenyl (N-methylcyclohexylamido)(p-tolylamido)phosphinate, C20H27N2O2P, (I), and rac-phenyl (allylamido)(p-tolylamido)phosphinate, C16H19N2O2P, (II), were synthesized from the racemic phosphorus–chlorine compound (R,S)-(Cl)P(O)(OC6H5)(NHC6H4-p-CH3). Furthermore, the phosphorus–chlorine compound ClP(O)(OC6H5)(NH-cyclo-C6H11) was synthesized for the first time and used for the synthesis of rac-phenyl (benzylamido)(cyclohexylamido)phosphinate, C19H25N2O2P, (III). The strategies for the synthesis of racemic mixed-amide phosphinates are discussed. The P atom in each compound is in a distorted tetrahedral (N1)P(═O)(O)(N2) environment. In (I) and (II), the p-tolylamido substituent makes a longer P—N bond than those involving the N-methylcyclohexylamido and allylamido substituents. In (III), the differences between the P—N bond lengths involving the cyclohexylamido and benzylamido substituents are not significant. In all three structures, the phosphoryl O atom takes part with theN—H unit in hydrogen bonding interactions, viz. an N—H…O═P hydrogen bond for (I) and (N—H)(N—H)…O═P hydrogen bonds for (II) and (III), building linear arrangements along [001] for (I) and along [010] for (III), and a ladder arrangement along [100] for (II).

Keywords