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प्रश्न
Explain the following reactions:
Stephan reaction
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उत्तर
This reaction is used to synthesize aldehydes from nitriles or cyanides. Firstly, nitriles or cyanides are reduced in presence of stannous chloride and hydrochloric acid in ethyl acetate solvent to form imine intermediate. Then hydrolysis of this intermediate with water gives the corresponding aldehyde.
\[\ce{CH3 - C ≡ N + 2[H] ->[SnCl2/HCl][Ether] CH3 - CH = NH + HCl ->[H2O/H^+] \underset{Acetaldehyde}{CH3CHO} + NH4Cl}\]
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संबंधित प्रश्न
Write the product in the following reaction
How will you prepare the given compound from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom.
p-Nitrobenzaldehyde
Ozonolysis of alkenes followed by the reaction with zinc dust and water gives ____________ depending on the substitution pattern of the alkene.
Name the electrophile produced in the reaction of benzene with benzoyl chloride in the presence of anhydrous \[\ce{AlCl3}\]. Name the reaction also.
Ethylbenzene is generally prepared by acetylation of benzene followed by reduction and not by direct alkylation. Think of a possible reason.
Match the example given in Column I with the name of the reaction in Column II.
| Column I (Example) |
Column II (Reaction) |
||
| (i) | \[\begin{array}{cc} \phantom{...}\ce{O}\phantom{..............................}\ce{O}\phantom{}\\ \phantom{...}||\phantom{..............................}||\phantom{}\\ \ce{CH3 - C - Cl + H2 ->[Pd - C/BasO4] CH3 - C - H} \end{array}\] |
(a) | Friedel Crafts acylation |
| (ii) |  |
(b) | HVZ reaction |
| (iii) |  |
(c) | Aldol condensation |
| (iv) | \[\begin{array}{cc} \ce{R - CH2 - COOH ->[Br/Red P] R - CH - COOH}\\ \phantom{.....................}|\\ \phantom{.......................}\ce{Br} \end{array}\] |
(d) | Cannizaro’s reaction |
| (v) | \[\ce{CH3 - CN ->[(i) SnCl2/HCl][(ii) H2O/H+] CH3CHO}\] | (e) | Rosenmund’s reductio |
| (vi) | \[\ce{2CH3CHO ->[NaOH] CH3 - CH = CHCHO}\] | (f) | Stephen’s reaction |
\[\begin{array}{cc}
\ce{CH3 - CH2 - CH - CH3}\\
\phantom{.....}|\\
\phantom{......}\ce{Cl}
\end{array}\] obtained by chlorination of n-butane, will be
The reaction of benzene with CO and HCl in the presence of anhydrous AlCl3 gives ______.
Assertion (A): Strong oxidising agents oxidise toluene and its derivatives to benzoic acids.
Reason (R): It is possible to stop the oxidation of toluene at the aldehyde stage with suitable reagents.
Select the most appropriate answer from the options given below:
Write the name of the reaction, structure and IUPAC name of the product formed when:
CH3CH2CN reacts with stannous chloride in the presence of hydrochloric acid, followed by hydrolysis.
