sodium hydroxide in tetrahydrofuran; methanol; water 0.5 h; Heating;

1: 78 percent / aq. NaOH / methanol; dimethylformamide / 0.5 h / 40 - 50 °C 2: 72 percent / 1-ethyl-3-<3-(dimethylamino)propyl>carbodiimide hydrochloride / dimethylformamide / 72 h / Ambient temperature 3: (dimethylamino)pyridine / pyridine / 0.17 h / Ambient temperature 4: 1.) trimethylsilyl chloride, NaI, 2.) triethylamine / 1.) acetonitrile, benzonitrile, 65 deg C, 45 min, reflux, 15 min View Scheme