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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
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
Write the structure of an isomer of compound C4H9Br which is most reactive towards SN1 reaction
Give reasons for the following:
(CH3)3C–O–CH3 on reaction with HI gives (CH3)3C–I and CH3–OH as the main products and not (CH3)3C–OH and CH3–I.
Write the isomers of the compound having the formula C4H9Br.
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH(Br)CH2CH3 + NaOH ->[water]}\]
Arrange the compounds of the following set in order of reactivity towards SN2 displacement:
1-Bromo-3-methylbutane, 2-Bromo-2-methylbutane, 2-Bromo-3-methylbutane
AgCN reacts with haloalkanes to form isocyanide. Haloalkanes react with KCN to form alkyl cyanides as the main product. Why?
Which one of the following halogen compounds is difficult to be hydrolysed by SN1 mechanism?
Tertiary alkyl halides are practically inert to substitution by SN2 mechanism because of ____________.
Which of the following alkyl halides will undergo SN1 reaction most readily?
Which reagent will you use for the following reaction?
\[\ce{CH3CH2CH2CH3 -> CH3CH2CH2CH2Cl + CH3CH2CHClCH3}\]
Which of the following statements are correct about this reaction?
(i) The given reaction follows SN2 mechanism.
(ii) (b) and (d) have opposite configuration.
(iii) (b) and (d) have same configuration.
(iv) The given reaction follows SN1 mechanism.
Chlorination of alkanes is an example of
Which one is the correct order of nucleophilic strength (pKa) of following nucleophiles?
When CH3CH2CHCl2 is treated NaNH2 product formed is:-
Which one of the following compounds is more reactive towards SN1 reaction?
The number of chiral alcohol (s) with molecular formula C4H10O is ______.
In SN1 reactions, the correct order of reactivity for the following compounds:
CH3Cl, CH3CH2Cl, (CH3)2CHCl and (CH3)3CCl is ______.
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 SN2 mechanism of methyl bromide using aqueous KOH.
