Magnesium-mediated ortho-specific formylation and formaldoximation of phenols

Abstract

Deprotonation of phenols using magnesium methoxide, followed by distillative removal of free methanol and addition of paraformaldehyde results in ortho-specific magnesium-mediated formylation to give the corresponding salicylaldehyde magnesium salts, from which the salicylaldehydes can be isolated by acidic work-up. Addition of aq. hydroxylamine sulfate to the salicylaldehyde magnesium salts, in place of the acid work-up, gives the corresponding salicylaldoximes.