The lithiation of various methyl substituted isoxazoles, isothiazoles, pyrazoles, oxadiazoles, and thiadiazoles using n-butyllithium has been studied. Three types of reactions, namely, lateral lithiation, ring cleavage, and addition of butyllithium to the ring, have been found. 3, 5- Dimethylisoxazole, 3-phenyl-5-methylisoxazole, 3, 4-dimethyl-1, 2, 5-oxadiazole, 2, 5- dimethyl-1, 3, 4-thiadiazole, 3-phenyl-5-methyl-1, 2, 4-oxadiazole, and 3, 5-dimethyl-1, 2, ...