含窒素環化合物の合成 (第121報)
ベンゾチアゾール誘導体について その11
1960 年 80 巻 2 号 p. 260-264
詳細
1960 年 80 巻 2 号 p. 260-264
In order to examine analgesic activity, dimethylaminoethyl and dimethylaminopropyl 6-chloro (methoxy or ethoxy)-2-benzothiazolecarboxylates were prepared. 2-Benzothiazolecarboxylic acids were obtained by the reaction of ethyl 4-chloro (methoxy or ethoxy)-oxanilate and phosphorus pentasulfide to form ethyl thioöxanilates, hydrolyzed with sodium hydroxide to thioöxanilic acids, and cyclized with potassium ferricyanide in alkaline aqueous solution. The acids were derived to the acyl chloride with phosphorus pentachloride and condensed with dimethylaminoethanol or dimethylaminopropanol. These esters underwent decomposition in the air to form 6-chloro-(methoxy or ethoxy)-benzothiazole.
Dimethyl- or diethyl-aminoethyl and dimethyl aminopropyl 6-chloro- or 6-ethoxy-2-benzothiazolepropionate were prepared by the application of sulfuric acid in methanol to N-(p-chlorophenyl)- or N-(p-ethoxyphenyl)-succinimide to form methyl succinanilates, reacted with phosphorus pentasuifide to form N-phenylthiosuccinimides, and cyclized with sodium hydroxide to thiosuccinanilic acids, which was further cyclized with potassium ferricyanide to 2-benzothiazolepropionic acids, derived to aryl chlorides with thionyl chloride, and finally condensed with dimethylaminoethanol, dimethylaminopropanol, or diethylaminoethanol.
