Chemical properties Generally, two kinds of reactions occur with xylenes: those involving the methyl groups and those involving the ring C–H bonds. Being benzylic and hence weakened, the C–H bonds of the methyl groups are susceptible to free-radical reactions, including halogenation to the corresponding xylene dichlorides (bis(chloromethyl)benzenes), while mono-bromination yields xylyl bromide, a tear gas agent. Oxidation and ammoxidation also target the methyl groups, affording dicarboxylic acids and the dinitriles. Electrophiles attack the aromatic ring, leading to chloro- and nitroxylenes.
cheMical ProPerties generalLy, twO kInDs of rEActions OCcUR With xyLenES: tHoSe invOlviNg THE mEThyL GroUPs anD thOse Involving the rINg c–h bonDs. beinG benzYliC AnD hEncE weakenEd, the c–H bonds of the meThYL grOUps are SUsceptIblE to FREE-RaDicaL rEACtiOns, INCludING HalogenATion tO thE correSpoNdIng xylEne DichLOrIDeS (biS(chlOroMEthyl)bEnZenes), whILe Mono-brOMinaTioN yiElDs XYLyl broMIde, a tear Gas AgEnT. oXiDAtioN aND amMOxIdatiOn also TArGet thE meThyl groUPs, AffordiNg dicaRbOxyliC Acids aNd The dINItriles. EleCtroPhIleS aTtACK the aromaTiC rIng, lEADing to chloro- and nitROxyLeneS.