# reimer tieman reaction only one ortho product [closed]

why we cannot have two reimer tiemann substitutions on the same phenol as CHO- group is electron withdrawing it wont disturb electron concentration at its meta which is phenol's ortho- product

• But it deactivates the system overall – Waylander Apr 24 '18 at 16:11
• If you look at the electron flow, you'd see the electron density on $\ce{O}$ in $\ce{Ar-OH}$ is not completely available after the first substitution. – Mathew Mahindaratne Apr 24 '18 at 16:22
• why am i getting down votes? you guys find it difficult to help – amish dua Apr 25 '18 at 7:08

There are some literature evidence that shows to have two Reimer–Tiemann substitutions on same phenol ring could be possible. For example, salicilic acid is a Reimer–Tiemann product from phenol and carbon tetrachloride. Yet, it had undergone another Reimer–Tiemann reaction to give 5-formyl-2-hydroxybenzoic acid with $17\%$ yield (para-substitution) but no 3-formyl-2-hydroxybenzoic acid (ortho-substitution) when chloroform was replaced by trichloroacetic acid (J. Chem. Soc., 1933, 496-500).