4- Methoxy-1 -phenyl quinoxaline

Methoxy-5-nitro-3-phenylquinoxaline gave only 6-methoxy-5-nitro-3-phenyl-quinoxaline 1-oxide (232) (AcOH, 30% H2O2, 80°C, 3 h 81%) 1,3-dimethyl-2(17/)-quinoxalinone 4-oxide (233) was made similarly but in only... 

Quinoxalinediamine (172) and p-methoxybenzoic acid gave 2-p-methoxy-phenyl-17/-imidazo[4,5-/]quinoxaline (174) [neat synthon (2 equiv), 210°C,... 

A sulfoxide was obtained by oxidation of 8-[(4-trifluoromethylmercapto-phenyl)methoxy] derivative 358 with 36% H2O2 in AcOH (98MIP7) and by oxidation of l-[2-(4-thiomorfolin-l-yl)acetyl]-7-(3-methoxyphenyl)-A-methyl-A- [3,5-bis(trifluoromethyl)phenyl]ethyl -5-oxo-1,2,3,5-tetrahydro-pyrido[l,2,3-i/ ]quinoxaline-6-carboxamide with 3-chloroperbenzoic acid (01MIP12). A 7-[(4-fluorophenylsulfonyl)methyl] derivative was obtained by oxidation of a 7-[(4-fluorophenylsulfanyl)methyl]perhydropyrido[l,2-u] prazine with 3-chloroperbenzoic acid in CHCI3 (01EUP1074257). 

Phenyl-6-trifluoromethylquinoxaline (229) gave 2-phenyl-6-trifluoromethyl-quinoxaline 4-oxide (230) (HCO2H, 30% H2O2, 50°C, 12 h 85% homologs similarly)6-methoxy- (231, R = OMe) and 6-nitro-3-phenylquinoxaline 1-oxide (231, R = N02), as well as other analogs, were made similarly in... 

Benzylidenehydrazino-3-methoxyquinoxaline (273) underwent oxidative cyclization to 4-methoxy-l-phenyl[l,2,4]triazolo[4,3-fl]quinoxaline (274) [Cu(OAc)2, AcOH, reflux, 1 h 80% " tetrachlorobenzoquinone, CICH2CH2 Cl, reflux, 90 min 92% " analogs by both procedures]... 

Methoxy-5,6-quinoxalinediamine (191) and glyoxal gave 5-methoxypyrazino [2,3-/]quinoxaline (192) (EtOH, H20, reflux, 1 h >70%) 195 2,3-di-phenyl-5,6-quinoxalinediamine and benzil likewise gave 2,3,8,9-tetraphenylpyra-zino[2,3-/]quinoxaline (193) (AcOH, reflux, 1 h %).955... 

Very little attention has been given to the metalation of the quinoxaline system, although lithiation of the 2-methoxy and 2-methylthio derivatives has recently been achieved (Scheme 118) (91JHC765). Reaction with N-methoxy-/V-methylbenzamide occurred at -78°C to give the analogous phenyl ketones in moderate yield. Highly colored insoluble solids were also produced, and these were the sole products when metalation of 2-chloroquinoxaline was attempted. 

Phenylquinoxalin-2(l/f)-one reacts with 3-dimethylaminopropylmagnesium chloride at the carbonyl carbon to give 2-(3-dimethylaminopropyl)-3-phenylquinoxaline in 30% yield. Nucleophilic substitution of the methoxy group in 2-meihoxyquinoxaline (19) with phenyl-acetonitrile in the presence of sodium hydride yields a-phenyl-a-(quinoxalin-2-yl)acetonitrile (20). "" ... 

The fluorescence and phosphorescence of quinazoline, 6-chloro-4-phenyl-and 6-chloro-l-methyl-4-phenylquinazolin-2(lH)-one were recorded in ethanol containing 1% of concentrated sulfuric acid. The luminescence of these compounds on thin-layer chromatography (TLC) plates saturated with ethanol was reported. 4-Morpholino- and 4-piperidino-6-methoxy-2-phenyl-quinazoline also have luminescent properties, and the ultraviolet fluorescence in the crystals and in hexane or benzene solution was discussed. The time and wavelength resolved emission from quinazoline vapor at low pressures was studied with a pulsed frequency double-dye laser and were compared with those of quinoxaline and cinnoline. ... 

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