3-Bromo-7- -cinnolinone

Quinolin-4-one forms a 3-bromo derivative, but coumarin gives the addition compound (116) which is easily re-aromatized (116 — 117). 4-Thiopyrones are halogenated in position 3. Pyridazinones and cinnolinones are also readily halogenated in the expected position. [Pg.191]

Bromo-2,3-dimethoxy-12//-[l]benzopyrano[2,3-c]cinnoUn-12-one (190) underwent hydrolytic ring fission to 4-(3-bromo-6-hydroxybenzoyl)-6,7-dime-thoxy-3(27/)-cinnolinone (191) (NaOH, H2O, no further details > 60%). ... [Pg.28]

Bromo-4(17/)-cinnolinone (44) gave 4-oxo-l,4-dihydro-3-cinnolinecarbonitiile (45) (CuCN, pyridine, reflux, 16 h 92%). ... [Pg.52]

Bromo-l-phenyl-7-(pyridin-4-yl)-4(l//)-cinnolinone (46, R = Br) gave 4-oxo-l-phenyl-7-(pyridin-4-yl)-l,4-dihydro-3-cinnolinecarbonitrile (46, R = CN) (CuCN, MeaNCHO, reflux, 18 h crude nitrile), characterized by conversion into 4-0X0- l-phenyl-7-(pyridin-4-yl)-1,4-dihydro-3-cinnolinecarboxylic acid (46, R = C02H) (50% H2SO4, 110°C, 12 h 33% overall). ... [Pg.52]

Bromo-4-oxo-l-propyl-l,4-dihydro-3-cinnolinecarboxylic acid (16, R = C02 H) gave 6-bromo-l-propyl-4(l/l)-cinnolinone (16, R = H) (neat substrate. [Pg.98]

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