Advertisements
Advertisements
Question
Write a note on Stephen reaction.
Solution
Nitriles are reduced to imine hydrochloride by stannous chloride in presence of hydrochloric acid which on acid hydrolysis give corresponding aldehydes. This reaction is called Stephen reaction.
\[\ce{\underset{(Alkane nitrile)}{R - C ≡ N +}2[H] ->[SnCl2, HCl]\underset{(Imine hydrochloride)}{R - HC = NH.HCl}->[H3O+]\underset{(Aldehyde)}{R - CHO} + NH4Cl}\]
e.g. \[\ce{\underset{(Ethanenitrile)}{H3C - C ≡ N}+2[H] ->[SnCl2, HCl][(reduction)]\underset{(Ethanimine hydrochloride)}{CH3 - HC = NH.HCl}->[H3O+]\underset{(Ethanal)}{CH3 - CHO} + NH4Cl}\]
RELATED QUESTIONS
Choose the most correct option.
Benzaldehyde does NOT show positive test with ______.
Addition of sodium bisulphite to ethanol is ____________ type of reaction.
Write the name of the product when ketones react with 1,2-diol in presence of dry HCl.
Explain haloform reaction with suitable example.
Ethyl methyl ketone can be reduced to n-butane by which of the following reactions?
Acetone reacts with iodine (I2) to form iodoform, in the presence of ____________.
Fehling solution is ____________.
Compounds of general formula, are called ____________.
\[\begin{array}{cc} \phantom{...}\ce{R}\phantom{....}\ce{OR'}\phantom{}\\ \phantom{}\backslash\phantom{..}/\\ \ce{C}\\ \phantom{}/\phantom{..}\backslash\\ \phantom{...}\ce{H}\phantom{....}\ce{OR'}\phantom{} \end{array}\]
The compound which does NOT undergo haloform reaction is ____________.
Identify the product Y in the following series of reactions.
\[\ce{4-Nitrotoluene ->[(CH3CO)2O/CrO3][273 - 278 K] X ->[H3O^+][\Delta] Y}\]
Predict the product Z in the following series of reactions.
\[\ce{Ethanoic acid ->[PCl5] X ->[C6H6][Anhydrous AlCl3] Y ->[i) CH3MgBr][H3O^+] Z}\]
Phenyl methanal is reacted with concentrated NaOH to give two products X and Y. X reacts with metallic sodium to liberate hydrogen X and Y are ____________.
Identify A, B, C and D.
\[\ce{ethanoic acid ->[SOCl2] A ->[Pd/BaSO4] B ->[NaOH] C ->[][\Delta] D}\]
What is the action of HCN on propanone?
What is the action of HCN on 2, 4-dichlorobenzaldehyde?
Write the structure of the major product of the aldol condensation of benzaldehyde with acetone.
How is the following conversion effected Hex-3-yne into hexan-3-one?
Complete the following reaction.
\[\begin{array}{cc}
\ce{CH3 - CH2 - CH2 - C - CH3 ->[HO - CH2 - CH2 - CH2 - OH][dry HCl] ?}\\
||\phantom{.........}\\
\ce{O}\phantom{.........}
\end{array}\]
Identify A, B and C.
How will you prepare acetic anhydride from acetic acid?
How will you prepare acetophenone from acetyl chloride?
How will you prepare cinnamic acid from benzaldehyde?
Which of the following compound will show a positive silver mirror test?
Primary nitroalkanes are obtained in good yield by oxidising aldoximes with the help of ______.
Which one of the following substituents at para-position is most effective in stabilizing the phenoxide 
ion?
Identify the reaction in which carbonyl group of aldehydes and ketones is reduced to methylene group on treatment with zinc-amalgam and cone. HCI.
How are the following compound obtained from alkyne?
Acetaldehyde
Write a note on Clemmensen reduction.
Write the structure of the products obtained from the following ketones by action of hydrazine in presence of a slightly acidic medium.
