Preparation | Using 5-chloro-2-furanformaldehyde as raw material, it is prepared by oxidation or Cannizzaro reaction (Cannizzaro reaction). It is prepared by air oxidation of 5-chloro-2-furaldehyde. The reaction is carried out at 45°C with strong stirring. The reactant is filtered to recover the catalyst copper oxide, the filtrate is acidified with sulfuric acid to a pH of 3-2.5, and furfuric acid is obtained by suction filtration, water washing and drying. 5-chloro -2-furfural in neutral or alkaline medium, oxidized with sodium hypochlorite or potassium permanganate for 2 hours, and then acidified with hydrochloric acid, furfuric acid can also be prepared, and the yield can reach about 98%. |