Doubt From General Organic Chemistry

MetaCyanoAniline
MetaHydroxyAniline
MetaMethoxyAniline
Basic Order pls!

in meta position consider only inductive effect
hence

order would be methoxy>hydroxy>cyano

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yes i know bro.
bt ans given is cyanide>methoxy>hydroxy
pls look into it @Chirag_Hegde @Viraam_Rao

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Nvm

@Aayush
Ohh I would have actually thought the answer is what you and Rama Chandra got. :thinking:

ok guys

they might have given pkb order

Had it been para instead of meta what would be the correct order ?
methoxy>hrdroxy>cyano?
@Viraam_Rao @Aayush

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Acidic order
Given answer is D
My doubt is how to compare P and R
@Supreeta_Sen @Viraam_Rao


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@Supreeta_Sen @seshu_ram

Fir 1st, I had asked same to my teacher. He had said that, there will be little h bonding b/w OH and H of CH3. Thus, H+ not easily released.

For 110, Q will be least because of steric factor.
Rest compare by Inductive

But H bonding occurs only with N, O ,F right? How can C-H take part in H bonding?

I meant H of Ch3. It is negligible in all other cases but for this question, he said he couldn't think of any other explanation.

Yeah exactly C-H bond is not polar enough to participate in H bonding


And why is Q least? In 110 how is sterics affecting acidity here

For the last, meta on will be the leat basic.
Q will be second last coz of steric factor.

By steric factor i meant ortho effect.

In 110 Ortho effect is overweighing Hyperconjugation
But in 111 +M is overweighing Ortho effect
Reason?

+M would destabilise more imo. I can't surely compare it with ortho as to why it will more.
But, mesomeric/resonance is always stronger than hyc. So, seemingly ortho effect is b/w the two.

See in some cases like here conjugation is taken into consideration before ortho effect. In meta position as we know +R is ineffective. Therefore only the negligible inductive effect of OCH3 is effective at meta. The conjugation is effective in both ortho and para positions thus making them more electron rich. But the extent of +R in ortho position is low which is the only explanation I can give for Q>P but however, even though it is negligible it is something... But maybe it is possible for SIR to affect this trend in basicity.

Okay read through a couple of web articles and inferred something new. At the ortho position both inductive and resonance effect acts. However, inductive effect appears to win over resonance at the ortho position.

How are you comparing the meta and Ortho isomers
They have opposite order in both of them

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