A. Alberola et al., COMPARATIVE REACTIVITY OF 3-METHYL-5-PHENYLISOXAZOLE AND 3-METHYL-5-PHENYLISOTHIAZOLE AGAINST ELECTROPHILIC COMPOUNDS, Journal of heterocyclic chemistry, 32(2), 1995, pp. 537-541
A comparative study of reactions of 3-methyl-5-phenylisoxazole and 3-m
ethyl-5-phenylisothiazole with electrophilic compounds in the presence
of n-BuLi, LICA or LICA-TMEDA is reported. By using LICA-TMEDA, regio
selective reactions of the heterocyclic compounds at the C-3 methyl gr
oup are obtained. With n-BuLi or LICA and the isoxazole derivative a p
roduct mixture at the C-4 position and the C-3 methyl group is found.
In the case of isothiazole compound, only with methyl iodide and n-BuL
i, the dialkylated product at both positions is formed.