1: 1.) xylene, reflux, 5 h, 2.) xylene, reflux, 15 h 2: 60 percent / concd. sulfuric acid, nitric acid / 2 h / 10 °C 3: 84 percent / H2 / 5percent Pd/C / ethyl acetate View Scheme

urea in xylene 16 h; Heating;

1: 89 percent / urea / xylene / 16 h / Heating 2: HNO3, H2SO4 / 16 h / 0 °C 3: 85.2 percent / H2 / Pd/C / ethanol 4: 48 percent / Et3N / tetrahydrofuran / 4 h / Heating View Scheme