• Condensation with aldehydes gives azlactones, which are intermediates in a classical route to amino acids; see, e.g.: Org. Synth. Coll., 2, 489 (1943). An alternative approach involves alkylation of the trianion of hippuric acid, prepared by LDA/TMEDA in THF: Tetrahedron Lett., 2205 (1976).
• For cyclization with acetic anhydride to 2-phenyl-5-oxazolone, see: Org. Synth. Coll., 5, 946 (1973).