Q55. Number of compounds from the following which cannot undergo Friedel-Crafts reactions is: $\_\_\_\_$。 toluene, nitrobenzene, xylene, cumene, aniline, chlorobenzene, $m$-nitroaniline, $m$-dinitrobenzene
Q55. Number of compounds from the following which cannot undergo Friedel-Crafts reactions is: $\_\_\_\_$。 toluene, nitrobenzene, xylene, cumene, aniline, chlorobenzene, $m$-nitroaniline, $m$-dinitrobenzene