Crystallized. Melting point 130-131°C (132.5-134°C).
3,4-Dihydroxy-5-methoxybenzaldehyde may be used for the preparation of 3,4-dihydroxy-6-methoxy-β-nitrostyrene and 5-hydroxyconiferyl alcohol.
3,4-Dihydroxy-5-methoxybenzaldehyde can be obtained by reactting 5-iodovaniliin with sodium hydroxide and copper sulfate solution.
The bromination reaction of vanillal and bromine generate 5-bromovanillal, which is then reacted with sodium hydroxide solution under the participation of copper powder to give 5-Hydroxyvanillin.
