Question

Based on your result comment on the relative “activating strength” of methoxy and hydroxy groups in electrophilic aromatic substitution.

(product being 5-Bromovanillin) from reactin standard Vanillin with Acetic acid, Hydrobromic acid, and Potassium Bromate in a directive effect reaction

Answer 1

activation or deactivation of the benzene ring toward electrophilic substitution may be correlated with the electron donating or electron withdrawing influence of the substituents.
The substituent effects of P-hydroxy and p-methoxy compounds is similar, but ortho compounds it is different, o-methoxy is having more comared to o-hydroxy compound.here we have to consider the meta effect of aldehyde group.