A novel route to the synthesis of 6,7,8,9-tetrahydro-[1,2,4]triazolo[5,1-b]quinazoline derivatives 4 through 5 and 6 was elaborated. During the synthesis of derivatives 6 novel type tetracyclic 2,3,7,8,9,10-hexahydro1,3a,5,6,10c-pentaazaacephenanthrylenes 9 were formed as by-products. Their structure was proved by spectroscopic methods and by X-ray diffraction spectra. There were also elaborated direct synthetic routes to derivatives 9. Unexpectedly, the S-alkyl groups of derivatives 9 could be easily replaced by different amines, which is contrary to all our previous results. Possible explanations to this enhanced reactivity are given.
ASJC Scopus subject areas
- Organic Chemistry