申请人:Bayer Aktiengesellschaft
公开号:US04888432A1
公开(公告)日:1989-12-19
2-Aminothiophenes of the formula ##STR1## wherein R=substituent and n=0-4, are prepared by dehydrogenating ring closure of thioamides of the formula ##STR2## The 2-aminothiophenes are useful for preparing useful azo dyestuffs. A process for preparing a compound of the formula ##STR3## comprising reacting a compound of the formula ##STR4## in which R and n have the abovementioned meanings with a compound of the formula ##STR5## in which T denotes NH.sub.2, aryl or alkyl, in the presence of an acid. An azo dyestuff of the formula ##STR6## in which V denotes Cl, Br or CF.sub.3, W denotes Cl, Br or NO.sub.2, R.sub.1 denotes hydrogen, halogen, alkyl, alkoxy, alkoxyalkyl or aryloxy, R.sub.2 denotes alkenyl or OH-, halogen-, CN-, CO.sub.2 -alkyl-, aryl-, cycloalkyl-, alkoxy-, aryloxy-, OCO-alkyl-, OCO-aryl-, OCONH-alkyl- or OCO.sub.2 -alkyl-substituted alkyl, R.sub.3 denotes hydrogen or identical or different R.sub.2 and R.sub.2 denotes hydrogen, alkyl, alkenyl, cycloalkyl, aralkyl, alkoxy, halogen, CF.sub.3 NHCO-alkyl, NHCO-aryl, NHCO.sub.2 -alkyl, NHCHO, NHSO.sub.2 -alkyl, NHCONH.sub.2, NHSO.sub.2 -aryl, NHSO.sub.2 -alkenyl, NHCONH-alkyl or NHCON-(alkyl).sub.2.
公式为##STR1##其中R=取代基,n=0-4,通过脱氢环合法制备。脱氢环合反应的起始物为公式##STR2##。2-
氨基
噻吩可用于制备有用的偶氮
染料。制备公式##STR3##化合物的方法包括在酸的存在下,将具有上述含义的R和n的化合物##STR4##与化合物##STR5##反应,其中T表示NH.sub.2,芳基或烷基。公式##STR6##中V表示Cl,Br或CF.sub.3,W表示Cl,Br或NO.sub.2,R.sub.1表示氢,卤素,烷基,烷氧基,烷氧基烷基或芳氧基,R.sub.2表示烯基或OH-,卤素,CN-,CO.sub.2-烷基,芳基,环烷基,烷氧基,芳氧基,OCO-烷基,OCO-芳基,OCONH-烷基或OCO.sub.2-烷基取代的烷基,R.sub.3表示氢或相同或不同的R.sub.2,R.sub.2表示氢,烷基,烯基,环烷基,芳基烷基,烷氧基,卤素,CF.sub.3 NHCO-烷基,NHCO-芳基,NHCO.sub.2-烷基,NHCHO,NHSO.sub.2-烷基,NHCONH.sub.2,NHSO.sub.2-芳基,NHSO.sub.2-烯基,NHCONH-烷基或NHCON-(烷基).sub.2。