Strategies for Aromatic Synthesis Order of Group Substitution

Strategies for Aromatic Synthesis Order of Group Substitution 

Adding the nitro group first and the chloro group second avoids this problem because the nitro group is a meta director, the entering chlorine atom enters at the meta position. 

We also have to beware of the limitations of each type of substitution process. We recall that Friedel— Crafts acylation does not occur when the ring contains a meta-directing group. For example, we can make w-nitroacetophenone by nitration of acetophenone, but not from Friedel—Crafts acylation of nitrobenzene. 

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