1: 32 percent / acetic anhydride / 2 h / Heating 2: 87 percent / xanthine oxidase (AXO) / 120 h / 4N NaOH, potassium phosphate buffer, pH 8.0 View Scheme

With  sodium dithionite in  water 24 h;  Heating;   

Multi-step reaction with 2 steps 1: 96 percent / NH3(g) / propan-1-ol / 36 h / Ambient temperature2: 89 percent / Na2S2O4 / H2O / 24 h / Heating