結核菌に対する化学療法剤の研究 (第7報)

2-Salicylidenehydrazono-4-thiazolidone関連化合物の合成及び抗菌作用 その2

抄録

The compounds possessing structures related to 2-salicylidenehydrazono-4-thiazolidone (I) and its 5-methyl derivative (II) were prepared and their antibacterial action in vitro was examined. 2-[(β-Hydroxy-α-naphtylmethylene) hydrazono]-4-thiazolidone, 2-o-acetoxybenzylidenehydrazono-4-thiazolidone, and their 5-methyl derivatives showed somewhat poorer action than (I) or (II) but still retained the antibacterial activity. However, the compounds with hydroxyl in the benzene ring situated in the meta- or para-position of the action group, =N-N=CH-, such as 2-m- or 2-p-hydroxybenzylidenehydrazono-4-thiazolidone and their 5-methyl derivatives, were entirely devoid of such action. Ten kinds of such compounds in which the hydroxyl in the ortho-position had been substituted with an alkoxyl (methoxy, ethoxy, propoxy, isopropoxy, and butoxy), and their respective 5-methyl derivatives also lacked such antibacterial activty. The foregoing results indicate that the following conditions must be fulfilled in order that the compounds show antibacterial activity.
1) Hydroxyl in the benzene ring must be situated ortho to =N·N=CH.
2) Hydroxyl must be in a free form or in a form that will easily change to the free hydroxyl.
These compounds were obtained by the reaction of aldehyde thiosemicarbazones and ethyl chloroacetate or ethyl α-bromopropionate, the presence of a neutralization agent, such as sodium acetate or N-ethylpiperidine, giving a good yield of the product.