The present invention provides a process for the preparation of 4-hydroxyindole derivatives of the general formula: ##STR1## in which R.sub.1 is a hydrogen atom or an alkyl radical containing up to 6 carbon atoms and R.sub.2 is a hydrogen atom or an alkyl radical containing up to 6 carbon atoms, wherein a compound of the general formula: ##STR2## in which R.sub.2 has the same meaning as above, is reacted with a compound of the general formula: R.sub.3 --CH.sub.2 --CO--COOR.sub.1 (III) in which R.sub.1 has the same meaning as above and R.sub.3 is a reactive residue, to give a 2-(2-imino-6-oxocyclohexylidene)-propionic acid derivative of the general formula: ##STR3## in which R.sub.1, R.sub.2 and R.sub.3 have the same meanings as above, which is then cyclized in known manner to give a compound of the general formula: ##STR4## in which R.sub.1 and R.sub.2 have the same meaning as above, which is subsequently dehydrated. The present invention also provides new 4-hydroxyindoles of general formula (I'), as well as new 4-Oxo-4,5,6,7-tetrahydroindoles of general formula (IV).
本发明提供了一种制备一般式为
4-羟基吲哚衍
生物的方法:其中R.sub.1是氢原子或含有多达6个碳原子的烷基基团,R.sub.2是氢原子或含有多达6个碳原子的烷基基团,其中一般式为的化合物:其中R.sub.2的含义与上述相同,与一般式为的化合物发生反应:其中R.sub.1的含义与上述相同,R.sub.3是反应性残基,得到一般式为的2-(2-亚
氨基-6-氧代环己基
亚乙酸衍
生物:其中R.sub.1、R.sub.2和R.sub.3的含义与上述相同,然后按已知方法环化,得到一般式为的化合物:其中R.sub.1和R.sub.2的含义与上述相同,随后脱
水。本发明还提供了新的一般式为的
4-羟基吲哚(I')以及新的一般式为的4-氧代-
4,5,6,7-四氢吲哚(IV)。