Oxidation method for preparing benzaldehyde from benzoic acid

(3) Benzaldehyde oxidation method

Add 50mmol benzaldehyde into a 50mL Erlenmeyer flask , and add a certain amount of Na ₂ WO ₄ ·2H ₂ O (as a catalyst) and NaHSO ₄ ·H ₂ O (the ratio of the two substances is 1:1), and magnetically stir.

Substitution of NaHSO ₄ ·H ₂ O with non-ionic surfactants can increase the yield.

The reaction equation is as follows:

(4) Phthalic anhydride heating decarboxylation method

This method can be divided into liquid phase method and gas phase method

(5) Benzyl halide oxidation method

Using benzyl halide as raw material and KMnO ₄ as oxidant, benzoic acid can also be prepared:

A 150mL conical flask was charged with 1g anhydrous sodium carbonate , 2.

(6) Household bleaching powder oxidation method

Put 350mL of bleach (0.

The water phase is cooled with ice, and 3mol/L H2SO4 is added until the solution becomes acidic, and a white precipitate of benzoic acid is obtained .

(7) Electrochemical synthesis method

Using chlorobenzene and CO ₂ as raw materials, N,N-dimethylformamide as the solvent, aluminum as the sacrificial anode, and stainless steel as the cathode, benzoic acid is prepared by electrochemical carboxylation in a non-diaphragm electrolytic cell at a water bath temperature of 5°C.

Related links: Benzyl alcohol oxidation method for the preparation of benzoic acid