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Compound A with the formula C8H9N2O2Cl is insoluble in water and base. Compound A slowly dissolves iAnalytical Chemistry Chemistry Question

A chemical puzzle

Compound A with the formula C8H9N2O2Cl is insoluble in water and base.
Compound A slowly dissolves in a dilute solution of hydrochloric acid.

13.1.

Which atom of A is involved in the reaction with HCl?

Model Answer

Nitrogen atom

13.2.

Compound A readily reacts with acetyl chloride yielding a product which is insoluble in acid and base.
Which functional group(s) in A can account for the reaction with acetyl chloride?

Model Answer

–NH2 or –NHR

13.3.

The 1H-NMR spectrum of A is shown in the figure:
[VISUAL]
Which groups can account for the signals a and b?

Model Answer

–CH2CH3

13.4.

Which functional group is involved in the reaction with Sn/HCl?

Model Answer

–NO2

13.5.

Draw the structure(s) of A that can be deduced on the basis of the information given. (Hint: Compound A does not react with a solution of silver nitrate, even not on heating.)

Model Answer

No AgNO3 reaction ⇒ no aliphatic chlorine substituent.
[VISUAL]
Possible structures of A are the isomers N-ethyl-2-chloro-4-nitroaniline and N-ethyl-3-chloro-4-nitroaniline.

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