Synthesis of some N‐[pyridyl(phenyl)carbonylamino]hydroxyalkyl‐(benzyl)‐1,2,3,6‐tetrahydropyridines as potential anti‐inflammatory agents

Abstract 1,2,3,6‐Tetrahydropyridines are known to possess analgesic, anti‐inflammatory, hyperglycemic and hypoglycemic activities. Substituted 2,4‐dinitrophenylpyridinium chlorides 3 were formed by reacting 1‐chloro‐2,4‐dinitrobenzene with hydroxypropyl, hydroxymethyl and benzyl substituted pyridines 2 . Attack of the pyridinium chlorides 3 with pyridylcarbonyl hydrazides or benzoyl hydrazides 4 gave the isolable 2,4‐dinitroanilino derivative 5 which underwent hydrolysis when refluxed in water: p ‐dioxane mixture (1:4 v/v) to afford the pyridinium ylides 6 . Sodium borohydride reduction of 6 in absolute ethanol at 0° for 4–6 hours resulted in the isolation of the 1,2,3,6‐tetrahydropyridines 7 in good yields.