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Investigation of the reactions of fluorine containing 3‐hydrazino‐5 H ‐1, 2, 4‐triazino[5, 6‐ b ]indoles with ethyl acetoacetate. Synthesis of some novel tetracyclic ring systems
Author(s) -
Joshi Krishna C.,
Dandia Anshu,
Baweja Sunita
Publication year - 1989
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570260304
Subject(s) - chemistry , ethyl acetoacetate , indole test , imidazole , hydrazone , ring (chemistry) , stereochemistry , medicinal chemistry , derivative (finance) , organic chemistry , catalysis , financial economics , economics
Novel tetracyclic ring systems viz. 3‐methyl‐1‐oxo‐12 H ‐1, 2, 4‐triazepino[3′,4′:3, 4][1, 2, 4]triazino[5, 6‐ b ]indole ( 4a ) and 3‐methyl‐5‐oxo‐12 H ‐1, 2, 4‐triazepino[4′,3′:2, 3][1, 2, 4]triazino[5, 6‐ b ]indole ( 5a ), having angular and linear structures respectively, were synthesized by the cyclization of 3‐oxobutanoic acid [5 H ‐1, 2, 4‐triazino‐[5, 6‐ b ]indole‐3‐yl]hydrazone ( 3a ). However, cyclization of 3b (R = CH a , R 1 = R 2 = H) afforded the angular product 4b exclusively. Moreover, cyclization of 3c (R = R 3 = H, R 1 = F) yielded 7‐fluoro‐1‐0xo‐10 H ‐1, 3‐imidazo[2′,3′:3, 4][1, 2, 4]triazino[5, 6‐ b ]indole ( 6c ) and 7‐fluoro‐3‐oxo‐10 H ‐1, 3‐imidazo[3′,2′:2, 3][1, 2, 4]triazino‐[5, 6‐ b ]indole ( 7c ) instead of the expected triazepinone derivatives. Compound 3d (R = R 1 = H, R 2 = CF 3 ) also gave an imidazole derivative but only one angular product was obtained. In all these reactions, formation of the angular product involving cyclization at N‐4 is favoured. Characterization of these products have been done by elemental analyses, ir, pmr, 19 F nmr and mass spectral studies.