抄録
The author synthesized the coumarin derivatives, substituted a hydroxy radical for the carbon atom at the 5th position of 3-acetyl-4-hydroxycoumarin, to xamine the effect on the antibacterial activity of the negative substituent in benzene nucleus of the coumarin.
The schema of the synthesis was illustrated by a chart. 2, 6-Dihydroxybenzaldehyde was prepared as a needle, m. p. 116°, from resorcin, introducing an aldehyde between the two hydroxyl groups by Gatterman's reaction, acetylating these hydroxy groups, and then oxidating the aldehyde to carboxylic group. In this oxydation, the yield of diacetoxy-benzoic acid was found to be. best when three times as much of KMnO4-were used as it was theoretically calculated. 3-Acetyl-4, 5-dihydroxycoumarin, mp. 158°, was obtained in 30% of the yield, condensing 2, 6-diacetoxybenzoic acid chloride with sodium acetoacetic acid ethyl ester in the solution of the dried ether. In this case, almost no 3-acetyl-4-hydroxy-5-acetoxycoumarin was obtained.
The antibacterial activities of these derivatives of coumarin will be published in the following paper.
