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प्रश्न
How do you convert the following:
Ethanol to propanenitrile
How the following conversion can be carried out?
Ethanol to propanenitrile
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उत्तर १
\[\ce{\underset{Ethanol}{CH3 - CH2 - OH} ->[red P/Br2] \underset{Bromoethane}{CH3 - CH2 - Br} ->[KCN, aq.ethanol]\underset{Propanenitrile}{CH3 - CH2 - CN}}\]
उत्तर २
\[\ce{\underset{Ethanol}{CH3CH2OH} ->[P/I2, \Delta] \underset{Iodoethane}{CH3CH2I} ->[KCN/EtOH-H2O][nucleophilic substitution] \underset{Propanenitrile}{CH3CH2CN}}\]
Notes
Students can refer to the provided solutions based on their preferred marks.
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संबंधित प्रश्न
Discuss the mechanism of alkaline hydrolysis of bromomethane.
Write the structure of the major product in each of the following reaction :
In the following pair of halogen compounds, which compound undergoes a faster SN1 reaction?
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH(Br)CH2CH3 + NaOH ->[water]}\]
The treatment of alkyl chlorides with aqueous KOH leads to the formation of alcohols but in the presence of alcoholic KOH, alkenes are major products. Explain.
Answer the following question.
Write one stereochemical difference between SN1 and SN2 reactions.
In a coordination entity of the type [PtCl2(en)2]2+ which isomer will show optical isomerism?
Tertiary alkyl halides are practically inert to substitution by SN2 mechanism because of ____________.
Racemic compound has ____________.
Identify X and Y in the following sequence:
\[\ce{C2H5Br ->[X] Product ->[Y] C3H7NH2}\]
Assertion: KCN reacts with methyl chloride to give methyl isocyanide.
Reason: CN– is an ambident nucleophile.
Complete the following analogy:
Same molecular formula but different structures: A : : Non superimposable mirror images: B
Cyanide ion acts as an ambident nucleophile. From which end it acts as a stronger nucleophile in aqueous medium? Give reason for your answer.
Chlorination of alkanes is an example of
In SN1 reactions, the correct order of reactivity for the following compounds:
CH3Cl, CH3CH2Cl, (CH3)2CHCl and (CH3)3CCl is ______.
Retention of configuration is observed in ______.
Convert bromoethane to propanamine.
The following questions are case-based questions. Read the passage carefully and answer the questions that follow:
|
Nucleophilic Substitution: Influences of solvent polarity: The reaction rate (SN2) of 2-bromopropane and NaOH in ethanol containing 40% water is twice slower than in absolute ethanol. Hence the level of solvent polarity has an influence on both SN1 and SN2 reactions but with different results. Generally speaking, a weak polar solvent is favourable for SN2 reaction, while a strong polar solvent is favourable for SN1. Generally speaking, the substitution reaction of tertiary haloalkane is based on SN1 mechanism in solvents with a strong polarity (for example ethanol containing water). |
Answer the following questions:
(a) Why racemisation occurs in SN1? (1)
(b) Why is ethanol less polar than water? (1)
(c) Which one of, the following in each pair is more reactive towards SN2 reaction? (2)
(i) CH3 – CH2 – I or CH3CH2 – Cl
(ii)
OR
(c) Arrange the following in the increasing order of their reactivity towards SN1 reactions: (2)
(i) 2-Bromo-2-methylbutane, 1-Bromo-pentane, 2-Bromo-pentane
(ii) 1-Bromo-3-methylbutane, 2-Bromo-2-methylbutane, 2-Bromo-3- methylbutane
Discuss the mechanism of alkaline hydrolysis of methyl bromide.
Explain why Grignard reagents should be prepared under anhydrous conditions.
