Antibacterial Properties of 2- and 2, 3-Substituted 1, 4-Naphthoquinones. II

Antibacterial activities were tested with 2-propylmercapto-, 2-butylmercapto-, 2-allylmercapto-, 2-thiophenyl-, 2-p-thiocresyl-, 2-p-chlorothiophenyl-, 2-methylamino-, benzylamino-, 2-anilino-3-chloro-, 2-anilino-3-methylmercapto-, 2, 3-di(thiophenyl)-, 2, 3-di-(p-thiocresyl)-, 2, 3-dichloro-, and 2-chloro-3-hydroxy-1, 4-naphthoquinone, and results are shown in Tables I and II. There were no compounds that showed better results than 2-methylmercapto-and 2, 3-di(methylmercapto)-1, 4-naphthoquinone, reported in the previous paper, but dichloro- and allylmercapto-1, 4-naphthoquinone were found to possess a fair degree of antibacterial power. 2, 3-Di(thiophenyl)-1, 4-naphthoquinone gives two kinds of crystals according to the conditions of recrystallization, one of purple leaflets, and the other of orange red needles, m.p. 148°. The former was found to transit to the latter without melting at 100-105° to orange red crystals that melt at 148°.