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4- Methoxy quinoxaline

The nitration of 6-methoxyquinoxaline in concentrated sulfuric acid at 0°C gives 6-methoxy-5-nitroquinoxaline. The position of the nitro group is confirmed by reduction of the product to 5-amino-6-methoxy-quinoxaline identical with a sample prepared from 2,3,4-triamino-anisole and glyoxal ... [Pg.211]

Acetamido-5-methoxy-1,2-benzenediamine (prepared in situ by reduction of 1 -acetamido-2-methoxy-4,5-dinotrobenzene) gave 6-acetamido-7-methoxy-quinoxaline (104) (OHCCHO-2NaHS03 H20, 70°C, 2 h 96%). 4-Acetamido-2,3-diaminophenol (105) (prepared in situ by reduction of the 2,3-dinitro analog) gave 8-acetamido-5(l//)-quinoxalinone (106) (OHCCHO-2NaHS03-H20, reflux, Nji, 2 h 79%). °... [Pg.17]

Acetamido-5-methoxy-1,2-benzenediamine (prepared in situ by reduction of 1 -acetamido-2-methoxy-4,5-dinotrobenzene) gave 6-acetamido-7-methoxy-quinoxaline (104) (OHCCHO-2NaHS03H20, 70°C, 2 h 96%).282... [Pg.17]

Chloro-5-methoxy quinoxaline 1,4-dioxide 2-Chloro-6-methoxyquinoxaline 4-oxide... [Pg.382]

Ethoxycarbonyl-6,7-dimethyl-2-quinoxalinecarboxylic acid 2-(l-Ethoxycarbonylethyl)-3-methoxy quinoxaline 2-(2-Ethoxycarbonylethyl)-7-methylamino-8-nitroquinoxaline... [Pg.402]

Periluoroquinoxaline (23) reacts with sodium methoxide to give pentafluoro-3-methoxy-quinoxaline, tetrafluoro-2,3-dimethoxyquinoxalinc. and trifluoro-2,3,7-trimethoxyquinoxa-line.131... [Pg.409]

Conflicting reports on the nitration of phenazine have appeared, but the situation was clarified by Albert and Duewell (47MI21400). The early work suggested that 1,3-dinitroph-enazine could be prepared in 66% yield under standard nitration conditions however, this proved to be a mixture of 1-nitrophenazine and 1,9-dinitrophenazine (24). As with pyrazines and quinoxalines, activating substituents in the benzenoid rings confer reactivity which is in accord with valence bond predictions thus, nitration of 2-methoxy- or 2-hydroxy-phenazine results in substitution at the 1-position. [Pg.164]

Quinoxalinyl, 4-cinnolinyl, and 1-phthalazinyl derivatives, which are all activated by a combination of induction and resonance, have very similar kinetic characteristics (Table XV, p. 352) in ethoxylation and piperidination, but 2-chloroquinoxaline is stated (no data) to be more slowly phenoxylated. In nucleophilic substitution of methoxy groups with ethoxy or isopropoxy groups, the quinoxaline compound is less reactive than the cinnoline and phthalazine derivatives and more reactive than the quinoline and isoquinoline analogs. 2-Chloroquinoxaline is more reactive than its monocyclic analog, 2-chloropyrazine, with thiourea or with piperidine (Scheme VI, p. 350). [Pg.375]

Quinoxalin-2-ones are in tautomeric equilibrium with 2-hydroxy-quinoxalines, but physical measurements indicate that both in solution and in the solid state they exist as cyclic amides rather than as hydroxy compounds. Thus quinoxalin-2-one and its A -methyl derivative show practically identical ultraviolet absorption and are bases of similar strength. In contrast, the ultraviolet spectra of quinoxalin-2-one and its 0-methyl derivative (2-methoxyquinoxaIine) are dissimilar. The methoxy compound is also a significantly stronger base (Table II). Similar relationships also exist between the ultraviolet absorption and ionization properties of 3-methylquinoxalin-2-one and its N- and 0-methyl derivatives. The infrared spectrum of 3- (p-methoxy-benzyl)quinoxalin-2-one (77) in methylene chloride shows bands at 3375 and 1565 cm" which are absent in the spectrum of the deuterated... [Pg.229]

Quinoxaline A-oxides undergo rearrangement under a variety of conditions. Thus on treatment of 2-ethoxy- and 2-methoxy-quinoxa-line 4-oxide with hydrochloric acid, rearrangement and hydrolysis occurs to give quinoxaline-2,3-dione. A possible intramolecular mechanism of rearrangement is shown in Scheme 7. Reaction of 2,3-... [Pg.234]

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). [Pg.304]

Dichloroquinoxaline (215) and 4-methoxy-l,2-benzenediamine gave 2-methoxy-5,12-dihydroquinoxalino[2,3-/7]quinoxaline (217) (Na2C03, Me2-NCHO, reflux, 5 h 60%) also many analogs somewhat similarly. ... [Pg.172]

Methoxy-5-quinoxalinamine (117, R = H) gave 6-methoxy-5,8-quinoxaline-quinone (118, R = H) [substrate hydrochloride, NaH2P04, H2O, 0N(S03K)2 (Fremy s salt) slowly, 20°C, 12 h 65%] ° 6-methoxy-3-morpholino-5-quinoxalinamine [117, R = N(CH2CH2)20] likewise gave 6-methoxy-3-morpholine-5,8-quinoxalinequinone [118, R = N(CH2CH2)20] (36%)/ ... [Pg.207]

Bromo-7-methoxy-5,8-quinoxalinequinone (148) and a-phenylstyrene (147) gave 5-phenylnaphtho[l,2-g]quinoxaline-7,12-quinone (150), probably via the intermediate (149) (PhH, pyridine, 20°C, hv, 30 min 12% analogs likewise but also in poor yield). [Pg.211]

Methoxy-5,8-quinoxalinequinone (205) gave 6-morpholino-(206, X = O) [0(CH2CH2)2NH, EtOH, reflux, 1 h 86%] or 6-piperidino-5,8-quinoxaline-... [Pg.221]

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... [Pg.226]

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... [Pg.226]

Quinoxalinediamine (172) and p-methoxybenzoic acid gave 2-p-methoxy-phenyl-17/-imidazo[4,5-/]quinoxaline (174) [neat synthon (2 equiv), 210°C,... [Pg.291]

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]... [Pg.309]

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... [Pg.294]

Methyl 5-methoxy-6,7-dimethyl-3-oxo-3,4-dihydro-2-quinoxalinecarboxylate Methyl 5-methoxy-6,7-dimethyl-3-oxo-3,4-dihydro-2-quinoxalinecarboxylate 1 -oxide Methyl 3-methoxy-2-quinoxalinecarboxylate 2-Methy l-3-( 1 -methylallyl)quinoxaline 2-Methyl-3-(2-methylallyl)quinoxaline 2-Methyl-3-methylaminomethylquinoxaline 5-Methyl-7-methylamino-8-nitro-2-phenylquinoxaline 5-Methyl-7-methylamino-8-nitro-3-phenylquinoxaline... [Pg.419]

See other pages where 4- Methoxy quinoxaline is mentioned: [Pg.371]    [Pg.382]    [Pg.402]    [Pg.411]    [Pg.411]    [Pg.255]    [Pg.327]    [Pg.360]    [Pg.197]    [Pg.206]    [Pg.308]    [Pg.366]    [Pg.65]    [Pg.197]    [Pg.206]    [Pg.221]    [Pg.308]    [Pg.366]   
See also in sourсe #XX -- [ Pg.308 ]

See also in sourсe #XX -- [ Pg.308 ]



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