2- Piperidino-5-nitropyridine

The ortho indirect deactivating effect of the two methyl groups in 2,6-dimethyl-4-nitropyridine 1-oxide (163) necessitates a much higher temperature (about 195°, 24 hr) for nucleophilic displacement of the nitro group by chloride (12iV HCl) or bromide ions N HBr) than is required for the same reaction with 4-nitropyridine 1-oxide (110°). With 5-, 6-, or 8-methyl-4-chloroquinolines, Badey observed 2-7-fold decreases in the rate of piperidino-dechlorination relative to that of the des-methyl parent (cf. Tables VII and XI, pp. 276 and 338, respectively). 

---