wiz-icon
MyQuestionIcon
MyQuestionIcon
14
You visited us 14 times! Enjoying our articles? Unlock Full Access!
Question

A compound X has molecular formula C7H7NO. On treatment with Br2 and KOH, X gives an amine Y. The later gives carbylamine test. Y upon diazotisation and coupling with phenol gives an azo dye. Thus, X is :

A
C6H5NO2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
C6H5COONH4
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
C6H5CONH2
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
none of the above
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C C6H5CONH2
1. C7H7NO, show the high degree of unsaturation, so it can be considered that there may be phenyl group, as phenyl group has 3 double bond.

2. As the compound C7H7NO, when reacts with Br2/KOH , gives the amine Y. It shows that there must be amide group in C7H7NO compound, as this reaction is Hoffmann Bromamide synthesis.

3. As this amine is synthesized by Hoffmann Bromamide synthesis, it gives carbylamine test, so it means that amine must be primary amine.

4. Now as upon diazotisation this amine forms diazonium salt, also it gives the coupling reaction with phenol to give an azo dye, then it must be aromatic diazonium salt. If it were aliphatic then it would form alcohol by releasing N2, and the coupling could not be possible.

So, all these steps show that this is C6H5CONH2.
Reactions:
1. C6H5CONH2(X)+Br2+4KOHC6H5NH2(Y)+K2CO3+2KBr+2H2O

2. C6H5NH2(Y)+CHCl3+3KOH+heatC6H5NC+3KCl+3H2O.

3. C6H5NH2(Y)NaNO2+2HCl(at 273278K)−−−−−−−−−−−−−−−−−C6H5N+2Cl+2NaCl+2H2O.

4. C6H5N+2ClC6H5OH/OH−−−−−−−−C6H5N=NC6H5OH(azo dye) .

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Chemical Reactions of Amines
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon