摘要 |
The invention relates to a method of preparing N-oxo-tetrahydro- beta -carbolines having formula 1. <CHEM> wherein - R1 is lower alkyl or alkoxy, halogen, trifluoromethyl, lower alkylthio, hydroxy, amino, lower mono- or dialkyl- or acylamino, - n has the value 0, 1 or 2, - R2 is hydrogen, lower alkyl or acyl, - R3 is hydrogen, lower alkyl or alkoxycarbonyl, or a phenyl group optionally substituted with a group R1, and - A together with the group -C-N-O-, forms a saturated heterocyclic ring system consisting of 6-8 ring atoms, wherein, in addition to the already present oxygen atom and nitrogen atom, an extra hetero atom from the group O, S and N may be present, which ring system may be substituted with one or more of the substituents alkyl,alkoxycarbonyl, alkanoyl, alkoxy, hydroxy, oxo, amino, mono- or dialkylamino, alkanoyl- or alkoxycarbonylamino, which ring system may be annelated with a saturated carbocyclic group of 5 or 6 ring atoms, by an intramolecular ringclosure reaction of compounds of formula 2 <CHEM> wherein Z is an aldehyde function or acetal function, or is a functional group which can be converted into such a function during the ringclosure reaction. The eudistomin derivatives within the group of compounds having formula 1 have strong antiviral and antitumour activity. |