Synthesis and herbicidal activity of N-substituted 2,6-bis(polyfluoromethyl)dihydropyridine-3,5-dicarboxylates

The synthesis and SAR of herbicidal N-substituted 2,6-bis(polyfluoromethyl)-1,2-dihydropyridine-3, 5-dicarboxylates are described. N-substituted dihydropyridines were readily prepared by treatment of the corresponding dihydropyridyl anions with electrophiles. Herbicidal activity of the N-substituted dihydropyridines is correlated with the rate of hydrolytic cleavage of the N-substituent to afford 2 or 3. Dihydropyridine 2 is shown to undergo oxidation in the soil to afford herbicidal 1, thereby relating the activity of N-substituted dihydropyridines to the corresponding aromatic herbicides