850 J. Org. Chem., Vol. 42, No. 5, 1977 Yovell, Hirsch, and Sarel authentic sample. The aqueous layer was acidified (hydrochloric acid) and extracted (ether). Evaporation of ether gave 0.41 g (68%) of diphenylacetic acid (13). Recrystallization of 13 from benzene gave colorless granules, mp 147-148" C. The melting point and IR spectrum of 13 were in good agreement with those of an authentic sample.