In the title compound, C(29)H(35)N(2)O(2)P, the stereogenic C center alpha to the P atom, formed during the Pudovik condensation reaction between a deprotonated chiral diazaphosphole and benzaldehyde, has disordered substituents, giving a mixture of Calpha-R and Calpha-S diastereoisomers. Moreover, this compound crystallizes with two independent molecules in the asymmetric unit. The observed configuration at the Calpha atom is 0.741 (6)-S mixed with 0.259 (6)-R, indicating diastereoisomeric enrichment during crystallization. Data from solution and solid-state studies consistently point to an epimerization process at the Calpha atom.