How to Predict where an Electrophilic Aromatic Substitution May Occur in a Ring – Part 4

An organic reaction in which an atom attached to an aromatic system (usually hydrogen) is substituted by an electrophile is referred to as electrophilic aromatic substitution (SEAr or EAS).


One of the most important EASs is diazotization (aka diazonium salt formation reaction, or diazoniation, or diazotation, or Griess diazo reaction), which is synthetically versatile as the salt can react with a variety of nucleophiles. These reactions take place by the aromatic nucleophilic substitution unimolecular mechanism (NAS, SN1Ar or SRN1).

During diazotization of primary arylamines, an excess of mineral acid is 'typically' used as the acid prevents the coupling of the diazonium salt formed with the arylamine by converting the arylamine to its salt (deactivation of the p-position of the arylamine).

An azo coupling is a reaction between an aromatic diazonium compound and an activated aromatic compound that produces an azo derivative.

Question:

Predict the major product(s) of the following reaction:



Click/tap to enlarge the image

Solution infographic:



Click/tap to enlarge the image

OPD = o-Phenylenediamine

For a wheel of diazotization reactions, click here.

Coupled with coupling reactions❓ Let Chemaficionado know in the comments below or at mychemistryhomework@gmail.com❗

References:

(1)    Wikipedia Contributors. Electrophilic aromatic substitution. Wikipedia. https://en.wikipedia.org/wiki/Electrophilic_aromatic_substitution.

(2)    Diazonium compound. Wikipedia. https://en.wikipedia.org/wiki/Diazonium_compound.‌

(3)    Azo coupling. Wikipedia. https://en.wikipedia.org/wiki/Azo_coupling.

‌(4)    Chouhan, M. S. Advanced Problems in Organic Chemistry for JEE, 11th Ed.

Comments

Post a Comment

Popular posts from this blog

How to Predict where an Electrophilic Aromatic Substitution May Occur in a Ring – Part 3

Image
An organic reaction in which an atom attached to an aromatic system (usually hydrogen) is substituted by an electrophile is referred to as  electrophilic aromatic substitution  ( S E Ar  or  EAS ). One of the most important  EASs  is halogenation. If Bromine water is added to Aniline, a multi-substituted product ( 2,4,6 -derivative) is obtained as Aniline is a strongly activating group (the same happens to Phenol). To generate the mono-substituted product, a protection, say, an acyl group is required. Question: Predict the major product(s) of the following reaction: Click/tap to enlarge the image Solution infographic: Click/tap to enlarge the image Motivated by EAS ❓ Let Chemaficionado know  in the comments below or at mychemistryhomework@gmail.com ❗ References: (1)      Wikipedia Contributors.  Electrophilic aromatic substitution . Wikipedia. https://en.wikipedia.org/wiki/Electrophilic_aromatic_substitution. (2)    ...
Read more

How to Carry out a Multistep Synthesis – Part 4

Image
Multistep synthesis  is the artificial execution of multiple organic chemical reactions to obtain one or more products by physical and chemical manipulations. Retrosynthetic analysis is a problem-solving approach in the organic syntheses, achieved by transforming a target molecule into simpler precursor structures regardless of any potential reactivity/interaction with reagents, and repeated until a simple or commercially available structure is reached, which can be used as a starting material to synthesize the target molecule. Question: How would you do the following transformation? Click/tap here to enlarge the image Solution infographic: Click/tap here to enlarge the image Let's keep in mind that any multistep synthesis is possible via several routes ❗Questions ❓ Let Chemaficionado know in the comments below or at mychemistryhomework@gmail.com ❗ References: (1)      Wikipedia Contributors.  Chemical synthesis . Wikipedia. https://en.wikipedia.org/wiki/Chemi...
Read more

How to Predict where an Electrophilic Aromatic Substitution May Occur in a Ring – Part 8

Image
An organic reaction in which an atom attached to an aromatic system (usually hydrogen) is substituted by an electrophile is referred to as  electrophilic aromatic substitution  ( S E Ar  or  EAS ). One of the most important  EASs  is nitration . Let's keep in mind that the presence of an activating group on the ring may complicate nitration. Question: Predict the major product(s) of the following reactions: Click/tap to enlarge the image Solution infographic: Click/tap to enlarge the image Eerie EAS chemistry❓ Let Chemaficionado know in the comments below or at mychemistryhomework@gmail.com ❗ References: (1)      Wikipedia Contributors.  Electrophilic aromatic substitution . Wikipedia. https://en.wikipedia.org/wiki/Electrophilic_aromatic_substitution. (2)      Brown, C.; Ford, M.  Higher Level Chemistry , 2nd ed.; Pearson Education: Harlow, Essex, 2014. ‌(3)     Electrophilic aromatic directing gro...
Read more