1: dimethyl sulfoxide; methanol / 2 h / 20 - 25 °C 2: sodium hydroxide; water / 3 h / 50 °C 3: potassium carbonate; p-toluenesulfonyl chloride; 4-(N,N-dimethlyamino)pyridine / N,N-dimethyl acetamide / 3 h / 30 °C View Scheme

1: dimethyl sulfoxide; methanol / 2 h / 20 - 25 °C 2: sodium hydroxide; water / 3 h / 50 °C View Scheme

in methanol; dimethyl sulfoxide T=20 - 25°C; 2 h;