Recent work in the apocupreine ether series3 has shown that on ascending in the series of alkyl ethers, a high pneumococcicidal activity is maintained through the C 4 derivatives. The situation is somewhat complicated by variations in the structure of the butyl group; however, isobutyl apocupreine dihydrochloride was shown to be as active in vitro as the very potent ethyl derivative. This is in marked contrast with the behavior of the corresponding ...
