2.3- Dihydro-4 -cinnolinone

The role of carbonyl compounds is dominant in the chemistry of dihydro derivatives of pyridazines. Dihydro-3 (2/ -pyridazinone derivatives are more stable than the corresponding simple dihydropyridazine derivatives and constitute the majority of dihydro compounds reported. The analogous derivatives are of course not possible in the phthalazine and cinnoline series, though 1,4-dihydro-3 (2/ -cinnolinones are known. [Pg.35]

Dimethyl-l,3-cyclohexanedione (dimidone, 145) and ethyl 2-(/7-tolylhydra-zono)acetoacetate (146) gave ethyl 4,7,7-trimethyl-5-oxo-l-p-tolyl-l,5,6,7-tetrahydro-3-cinnohnecarboxylate (147) (neat AcONEU, 170°C, 30 min 80%) " the same substrate (145) and benzil monohydrazone (148) gave 7,7-dimethyl-3,4-diphenyl-6,7-dihydro-5(l//)-cinnolinone (149) (or tauto-... [Pg.22]

Acetyl-1,4,4-triphenyl-l,2-diazetidin-3-one (162) rearranged into 2-acetyl-4,4-diphenyl-l,4-dihydro-3(2ff)-cinnolinone (163) (neat F3CCO2H >95% ... [Pg.24]

Cyclohexyl-6,7-dimethoxy-4(17/)-cinnolinone gave 4-chloro-3-cyclohexyl-6,7-dimethoxycinnoline (16) (neat POCI3, reflux, 30 min 60%) ° 4-0x0-l,4-dihydro-3-cinnolmecarbonitrile similarly gave 4-chloro-3-cinnolinecar-bonitrile (17) [140°C 120°C (bath temperature), 10 min 50%]. ... [Pg.48]

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]

C0CH2C1), 7,7-dimethyl-3-phenyl-4,6,7,8-tetrahydro-5( l//)-cinnolinone tautomer), and 2-ethoxycarbonyImethy 1-2,3-dihydro-4(l//)-cinnoli-also 6-lluoro- and 7-methyl-4-oxo-l,4-dihydro-3-cinnolinecarboxylic... [Pg.60]

Phenyl-5,6-dihydro-3(2//)-cinnolinone (21, R = H) gave 2-ethoxycarbonyl-methyl-7-phenyl-5,6-dihydro-3(2//)-cinnolinone (21, R = CH2C02Et) (Et02-CCHjBr, K2CO3, AcMe, reflux, 24 h 40%). ... [Pg.62]

Triphenylphosphoranylidene-3,4-dihydro-4-cinnolinone (25) gave l-methyl-3-triphenylphosphonio-4(lfl)-cinnolinone iodide (26) (neat Mel, reflux, h > 95%) and thence l-methyl-4(17/)-cinnolinone (27) (NaOH, MeOH, H2O,... [Pg.63]

Dimethyl-2,3-dihydro-4(l//)-cinnolinone (52, R = Me) gave 2-chloro-acetyl-6,7-dimethyl-2,3-dihydro-4(lfl)-cinnolinone (53) (CICH2CCXII, H2O,... [Pg.66]

C, h > 50%) and thence l,2-bis(chloroacetyl)-6,7-dimethyl-2,3-dihydro-4(l/f)-cinnolinone (54) (CICH2COCI, EtaN, see original for details) 2,3-dihydro-4(177)-cinnolinone (52, R = H) with 3-chloropropionyl chloride gave 2,3,5,6-tetrahydro-17/-pyrazolo[l,2-fl]cinnoline-3,6-dione (55) as the final product (PhH, reflux, 10 h 54%) " also another A -acylation. ... [Pg.67]

Dimethyl-3,4-diphenyl-6,7-dihydro-5(l//)-cinnolinon (62) with a-benzyl-idenemalononitrile gave 2-amino-5,5-dimethyl-4,9,10-triphenyl-5,6-dihydro-4//-pyrano[2,3-/]cinnoUne-3-carbonitrile (63) (Et3N, EtOH, reflux, 1 h 60%) ... [Pg.68]

Methyl-3(277)-cinnolinone (95) underwent reductive ring contraction to furnish 2-indolinone (96, R = H) (red P, HI 18%) in contrast, 2-methyl-1,4-dihydro-3(27/)-cinnolinone (97) underwent ring contraction by rearrangement to give l-methylamino-2-indolinone (96, R = NHMe) (H2SO4, EtOH,... [Pg.74]

Methoxy-8-nitro-4-oxo-l,4-dihydro-3-cinnolinecarboxylic acid (15, R = CO2H) gave 6-methoxy-8-nitro-4(l//)-cinnolinon (15, R = H) (Ph2CO, 190°C,... [Pg.98]

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]

This unusual transformation is exemplified in the isomerization of l-(o-methoxy-carbonylbenzoyl)-l,4-dihydro-3(2f/)-cinnolinone (189) into 2-[o-(methoxycarbonyl-methyl)phenyl]-l,4(2//,3//)-phthalazinedione (190) by refluxing in methanolic sulfuric acid or aqueous methanolic potassium hydrogen carbonate for 90 min or 7 h, respectively yields were unstated. ... [Pg.141]

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