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)
Let \( y = f(x) \) be the solution of the differential equation
\[ \frac{dy}{dx} + 3y \tan^2 x + 3y = \sec^2 x \]
such that \( f(0) = \frac{e^3}{3} + 1 \), then \( f\left( \frac{\pi}{4} \right) \) is equal to:
Find the IUPAC name of the compound.
If \( \lim_{x \to 0} \left( \frac{\tan x}{x} \right)^{\frac{1}{x^2}} = p \), then \( 96 \ln p \) is: 32