CN89105025 (1989)  Preparation of salicylaldehyde by catalytic oxidation of salicyl alcohol with non-noble metal complex 


The preparation of example 10, salicylic aldehyde
Under air atmosphere, saligenol (is formed by phenol and formaldehyde condensation, contain saligenol 38%), NaOH and methanol solvate join in the reactor, under agitation add western Buddhist alkali Salen-Co catalyzer, when containing pure saligenol 0.1mol during reaction in each raw material, use methyl alcohol 70ml, add solid NaOH4g, 1 controlling catalyst 0.005mol of example.60 ℃ of temperature of reaction are reflected under the normal pressure and carry out.
Reaction is reclaimed solvent methanol after distillation obtains the solid sodium phenolate.Add 150ml water dissolution solid sodium phenolate, be acidified to PH=3 with 0.5N sulfuric acid, carry out steam distillation, divide water-yielding stratum to obtain salicylic aldehyde, the yield of its salicylic aldehyde is 82%.
In above-mentioned reaction process and the condition, be raw material as the saligenol with 99.0%, then the yield of salicylic aldehyde is 97%.

NB Salen-Co catalyzer= complex Co+(ethyle diamine 2 salicyaldehyde)
others also acetyl acetonate or beta dicetonate