1: 63 percent / hydrazine, N,N-dimethylethanolamine 2: xylene / 1 h / Heating 3: 90 percent / xylene / 2.5 h / Heating 4: 96 percent / hydrogen / platinum black / ethyl acetate 5: 84 percent / dilute sulfuric acid 6: 97 percent / Wolff-Kishner reduction View Scheme