Number of compounds from the following which cannot undergo Friedel-Crafts reactions is :____
toluene, nitrobenzene, xylene, cumene, aniline, chlorobenzene, m-nitroaniline, m-dinitrobenzene
toluene, nitrobenzene, xylene, cumene, aniline, chlorobenzene, m-nitroaniline, m-dinitrobenzene
Correct Answer: 4
Solution and Explanation
Friedel-Crafts reactions require an aromatic compound and an electrophile, facilitated by a Lewis acid catalyst (e.g., AlCl$_3$). However,
certain compounds cannot undergo Friedel-Crafts reactions due to deactivating groups or coordination issues with the catalyst.
Toluene, xylene, and cumene: These are activated aromatic compounds and can undergo Friedel-Crafts reactions.
Chlorobenzene: Chlorine is an electron-withdrawing group but is ortho/para-directing; hence it can still undergo Friedel-Crafts reactions.
Nitrobenzene, m-nitroaniline, m-dinitrobenzene: Nitro groups are strongly deactivating, making the aromatic ring unreactive for Friedel-Crafts reactions.
Aniline: The amino group ($-\text{NH}_2$) coordinates with the Lewis acid catalyst (AlCl$_3$), deactivating the ring.
Compounds that cannot undergo Friedel-Crafts reactions:
Nitrobenzene, aniline, m-nitroaniline, m-dinitrobenzene (4 compounds).
Final Answer: (4)
Top Questions on Organic Chemistry
- Given below are two statements: Statement I: One mole of propyne reacts with excess of sodium to liberate half a mole of H₂ gas. Statement II: Four g of propyne reacts with NaNH₂ to liberate NH₃ gas which occupies 224 mL at STP. In the light of the above statements, choose the most appropriate answer from the options given below:
- JEE Main - 2025
- Chemistry
- Organic Chemistry
For the thermal decomposition of \( N_2O_5(g) \) at constant volume, the following table can be formed, for the reaction mentioned below: \[ 2 N_2O_5(g) \rightarrow 2 N_2O_4(g) + O_2(g) \] Given: Rate constant for the reaction is \( 4.606 \times 10^{-2} \text{ s}^{-1} \).
- JEE Main - 2025
- Chemistry
- Organic Chemistry
- Identify A and B in each of the following reaction sequence:
(a) \[ CH_3CH_2Cl \xrightarrow{NaCN} A \xrightarrow{H_2/Ni} B \]
(b) \[ C_6H_5NH_2 \xrightarrow{NaNO_2/HCl} A \xrightarrow{C_6H_5NH_2} B \]- CBSE CLASS XII - 2025
- Chemistry
- Organic Chemistry
A hydrocarbon which does not belong to the same homologous series of carbon compounds is
- CBSE Class X - 2025
- Science
- Organic Chemistry
- Carbohydrates are polyhydroxy aldehydes or ketones that represent enormous structural diversity in terms of the arrangement of atoms in space, resulting in hundreds of stereoisomers. Although the chemical properties of most stereoisomers may not be very different, their metabolic rate and utilization in biological systems is significantly different and known to influence the overall carbohydrate metabolism. Structural variants, which arise due to a different arrangement of atoms in three-dimensional space are known as stereoisomers. The number of stereoisomers can be theoretically estimated by using the formula 2n, where ‘n’ is the number of stereocenters or asymmetric (chiral) carbon atoms in a molecule. Out of these stereoisomers, there are some structures, which are mirror images of each other, and they are referred to as enantiomers.
- CBSE CLASS XII - 2025
- Chemistry
- Organic Chemistry
Questions Asked in JEE Main exam
- A force \( \mathbf{F} = 2\hat{i} + b\hat{j} + \hat{k} \) is applied on a particle and it undergoes a displacement \( \mathbf{r} = \hat{i} - 2\hat{j} - \hat{k} \). What will be the value of \( b \), if the work done on the particle is zero?
- JEE Main - 2025
- Work and Energy
- The number of different 5 digit numbers greater than 50000 that can be formed using the digits 0, 1, 2, 3, 4, 5, 6, 7, such that the sum of their first and last digits should not be more than 8, is:
- JEE Main - 2025
- permutations and combinations
- A body of mass \(4\) kg is placed at a point \(P\) having coordinates \( (3,4) \) m. Under the action of force \( \mathbf{F} = (2\hat{i} + 3\hat{j}) \) N, it moves to a new point \(Q\) having coordinates \( (6,10) \) m in \(4\) sec. The average power and instantaneous power at the end of \(4\) sec are in the ratio:
- The area of the region enclosed by the curves \( y = x^2 - 4x + 4 \) and \( y^2 = 16 - 8x \) is:
- JEE Main - 2025
- Area between Two Curves
- An AC current is represented as: $ i = 5\sqrt{2} + 10 \cos\left(650\pi t + \frac{\pi}{6}\right) \text{ Amp} $ The RMS value of the current is:
- JEE Main - 2025
- AC Circuits