engleski

Synthesis and Structure of Some 3, 4-Annelated Coumarin Systems

Refluxing of 4-chlorocoumarin-3-carbonitrile, heteroarylamines (3-aminopyrazole, 3-aminopyrazole-4-carbonitrile, 3-amino-1, 2, 4-triazole-5-thiol, 2-amino-6-fluorobenzothiazole, 2-amino-pyridin-3-ol, 1-aminoisoquinoline) and the catalytic amount of trimethylamine in acetonitrile gave the corresponding 3, 4-annelated coumarins 1-6 in high yields. The spectral analysis showed that 7-amino-5-oxa-7a, 8, 11-triazacyclopenta[b]phenantren-6-one (1) existed as enamine, 2 as a mixture of enamine 7-amino-6-oxo-5-oxa-7a, 8, 11-triazacyclopenta[b]phenantren-10-carbonitrile (2a) and imine 7-imino-6-oxo-7H, 8H-5-oxa-7a, 8, 11-triazacyclopenta[b]phenantren-10-carbonitrile (2b), whereas 10-fluoro-7-imino-7H-5-oxo-12-thia-7a, 13-diazaindeno[1, 2-b]phenantren-6-one (4), 11-hydroxy-7-imino-7H-7a, 12-diazabenzo[a]anthracen-6-one (5) and 7-imino-7H-5-oxa-7a, 14-diazadibenzo[a, h]anthracen-6-on (6) took imino forms.

nije evidentirano

nije evidentirano