N-Substituted Poly(«-amino acids) 1041 stirring at 95 °C until it became homogeneous. This required less than 1 h. Freshly cut sodium metal (0.40 g, 0.018 mol) was then added, and the resulting pink reaction mixture was heated at 95 °C and stirred for 1.5 h. Approximately one-half of the excess phenol was then removed by vacuum distillation. The concentrated reaction mixture was allowed to cool to 40 °C and concentrated HC1 (10 mL) was added, slowly, with stirring. The resulting suspension was poured into 20 volumes of methanol to precipitate the polymer, which was then washed with methanol and dried in vacuo. The yield was 0.54 g. Most of this sample was rephenylated, using the procedure described above, but a portion of it was reprecipitated from acetone into methanol, and then dried in vacuo. The infrared spectrum of this portion contained a strong absorption band at 1702 cm4. A portion of this sample was methylated with diazomethane.1 The NMR spectrum of the resulting product contained a strong resonance at ~3.5. Its intensity indicated that approximately 11.5% of the units were methyl methacrylate units.