1: 2.) N-methylmorpholine / 1.) methanol, reflux, 1 h, 2.) methanol, 2 h 2: 94.8 percent / 1N HCl, trifluoroacetic acid / 55 °C 3: sodium dithionite / dimethylformamide; H2O / 0.5 h 4: 0.1N NaOH / 1.5 h 5: Me2SO / dimethylformamide / 47 h 6: 0.1N NaOH / acetonitrile View Scheme