The tautomerism of heteroaromatic compounds with five-membered rings—II : 3-,4- and 5-amino- and acetamido-isoxazoles

Abstract

Infra-red and nuclear magnetic resonance spectra show that all types of amino- and acetamido-isoxazoles exist predominantly as such. Ultra-violet spectroscopy indicates that 3- and 5-amino-isoxazoles are protonated at the ring nitrogen atom, but the 4-amino- analogues on the amino- group. Basicities of these compounds are recorded.