sulfuric acid; nitric acid 0.166667 h; 1.) -10 deg C, 2.) steam bath;

1: 80 percent / 1 h / 220 °C 2: 85 percent / 1.) conc. H2SO4, fuming HNO3 / 0.17 h / 1.) -10 deg C, 2.) steam bath View Scheme