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प्रश्न
Write the equation involved in the following reaction:
Reimer-Tiemann reaction
Explain the following with an example.
Reimer-Tiemann reaction
उत्तर १
On treating phenol with chloroform in the presence of sodium hydroxide, a –CHO group is introduced at ortho position of benzene ring. This reaction is known as Reimer-Tiemann reaction. The intermediate substituted benzal chloride is hydrolysed in the presence of alkali to produce salicylaldehyde.
उत्तर २
Notes
Students should refer to the answers according to their questions and provide marks.
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संबंधित प्रश्न
Write the final product(s) in each of the following reactions:
Write the structures of A, B, C, D and E in the following reactions:
While separating a mixture of ortho and para nitrophenols by steam distillation, name the isomer which will be steam volatile. Give reason.
Give the equation of the following reaction:
Bromine in CS2 with phenol.
Name the reagent used in the following reaction:
Bromination of phenol to 2, 4, 6-tribromophenol.
Picric acid is ____________.
When phenol is treated with excess bromine water, it gives:
When phenol is heated with CHCl3 and alcoholic KOH when salicylaldehyde is produced. This reaction is known as ____________.
On distilling phenol with Zn dust, one gets:
In the reaction of phenol with CHCl3 and aqueous NaOH at 343 K, the electrophile attacking the ring is:
When Phenol is distilled with zinc dust, it gives:
The electrophile involved in Reimer-Tiemann reaction of phenol with CHCl3 in presence of NaOH:
Which of the following species can act as the strongest base?
Phenol does not undergo nucleophilic substitution reaction easily due to ______.
Which of the following are used to convert \[\ce{RCHO}\] into \[\ce{RCH2OH}\]?
(i) \[\ce{H2/Pd}\]
(ii) \[\ce{LiAlH4}\]
(iii) \[\ce{NaBH4}\]
(iv) Reaction with \[\ce{RMgX}\] followed by hydrolysis
Which of the following are benzylic alcohols?
(i) \[\ce{C6H5 - CH2 - CH2OH}\]
(ii) \[\ce{C6H5 - CH2OH}\]
(iii) \[\begin{array}{cc}
\ce{C6H5 - CH - OH}\\
\phantom{}|\phantom{.}\\
\phantom{..}\ce{CH3}\phantom{}
\end{array}\]
(iv) \[\begin{array}{cc}
\ce{C6H5 - CH2 - CH - OH}\\
\phantom{.......}|\phantom{}\\
\phantom{.........}\ce{CH3}\phantom{}
\end{array}\]
Nitration is an example of aromatic electrophilic substitution and its rate depends upon the group already present in the benzene ring. Out of benzene and phenol, which one is more easily nitrated and why?
Convert the following:
Phenol to N-phenylethanamide.
Which of the following is not aromatic?
Attacking species in nitration of benzene in presence of fuming HNO3 is
Why ortho-nitrophenol is steam volatile while para-nitrophenol is not?
For the pair phenol and cyclohexanol, answer the following:
Give one chemical test to distinguish between the two.
How can phenol be prepared from anisole? Give reaction.
Write the name of the reaction, structure and IUPAC name of the product formed when:
Phenol reacts with CHCl3 in the presence of NaOH followed by hydrolysis.
