Nucleophilic Substitution of Aryl Halides, SN2Ar

FIGURE 13.15 Relative rates of reaction of nitrated halobenzenes with methoxide ion. 

Explain the relative reactivity of the 2,4-dinitrohalobenzenes with piperidine  

FIGURE 13.21 Substitution of 3-halopyridines using microwave heating. 

The chlorine at the 2-position is much more easily substituted, because the charge in the intermediate can be located on the nitrogen atom. 

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