FORMATION OF THE PYRROLINE N-OXIDE RING BY INTERACTION OF α-ISONITROSOKETONES – DERIVATIVES OF TETRAHYDROBENZOFURAZAN AND -FUROXAN WITH ALDEHYDES AND MORPHOLINE AND SOME OF THE REACTIONS OF THESE COMPOUNDS
DOI:
https://doi.org/10.1007/s10593-005-0080-0Keywords:
enamines, α-isonitroso ketones, indolines, pyrroline N-oxides, 4,5,6,7-tetrahydrobenzofurazans, 4,5,6,7-tetrahydrobenzofuroxans, cinnolinesAbstract
α-Isonitroso ketones, derivatives of tetrahydrobenzofurazan and furoxan, react with aldehydes (acetaldehyde and propionaldehyde) and morpholine to form derivatives of tetrahydropyrrolo[2,3-e]-2,1,3-benzoxadiazole 6-oxide. Treatment of the latter with hydrazine hydrate gave derivatives of 4,5-dihydro-1,2,5-oxadiazolo[3,4-f]cinnoline which are readily dehydrogenated with tetrachloro-benzoquinone to derivatives of 1,2,5-oxadiazolo[3,4-f]cinnoline. Reduction of tetrahydropyrrolo[2,3-e]-2,1,3-benzoxadiazole 6-oxides with sodium borohydride gave derivatives of N-hydroxyhexahydro-pyrrolo[2,3-e]-2,1,3-benzoxazole.
Samsonov, V. A. Chem. Heterocycl. Compd. 2004, 40, 1346. [Khim. Geterotsikl. Soedin. 2004, 1558.]