Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

4- Ethyl quinoxaline

Hydroxyimino)ethyl]quinoxaline (112) gave 2-(l-cyano-2-dimethylami-... [Pg.277]

Hydroxyimino)ethyl]quinoxaline (112) gave 2-(l-cyano-2-dimethylami-novinyl)quinoxaline (113) [Me2NCH(OMe)2, PhMe, reflux, 10 min 10%].487... [Pg.277]

The ketoxime, 2-[l-(hydroxyimino)ethyl]quinoxaline (216), gave 3-methyl- 1H-pyrazolo[3,4-b]quinoxaline (217) (H2NNH2H20, HC1, H20, EtOH, reflux, 4 h 86%).995... [Pg.356]

Hydroxy ethyl)-3- methylquinoxaline 2-(2-Hydroxyethyl)-3-methylquinoxaline 2-(l-Hydroxyethyl)-3-pivalamidoquinoxaline 2- (2- Hydroxy ethyl) quinoxaline 2-(2-Hydroxyethyl)quinoxaline 1,4-dioxide 2-(2-Hydroxyethyl)-3,6,7-trimethylquinoxaline... [Pg.411]

Quinazoline (4 hydroxy) fenazaquin Quinoline (7 chloro 3.8 dimethyl) quinmerac Quinoline (7 chloro 8 methyl) quinclorac Quinoline, 2.3 dicarboxilic acid imazaquin Quinoxaline quinomethionate, quizalofop-ethyl Quinoxaline (2.6 dichloro) propaquizafop, quizalofop Quinoxaline (6 methyl 2.3 dichloro) chinomethionate Quinoxaline (2 hydroxy) quinalphos Quinoxaline (2 hydroxy, 6 chloro) propaquizafop... [Pg.1047]

Ethyl quinoxaline-2-carboxylate is obtained from quinoxaline and ethyl pyruvate hydrogen peroxide adduct [MeClOHXOjHlCOjEt], The latter is decomposed in the presence of aqueous iron(II) sulfate generating ethoxy carbonyl radicals. [Pg.232]

Reduction of the quinoxalines 5 leads to hydropyrroloquinoxalines 6-8 (Nelson and Boyer 1950 Okumura and Shigemitsu 1965). The pyrrolo[l,2-a]quinoxaline system (compound 6) was first obtained by this method (Okumura and Shigemitsu 1965). During the reductive cyclization of ethyl quinoxalin-2-yl- and 3-methylquinoxalin-2-ylpyruvates 5 in the presence of copper chromite at high temperature, the perhydropyrrolo[l,2-a]quinoxalines 7 and 8 are formed (Scheme 3.2). [Pg.137]

The formation of quinoxaline quaternary salts is often difficult. However, reaction of quinoxaline with ethyl iodide in boiling acetonitrile gives ethyl quinoxalinium iodide in 76% yield, and treatment of the parent base with methyl toluene-p-sulfonate at room temperature gives methyl quinoxalinium toluene-p-sulfonate in quantitative yield. ... [Pg.219]

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]

Ethyl 1 -substituted 7-hydroxy-5-oxo-1,2,3,5-tetrahydropyrido[ 1,2,3-<7e] quinoxaline-6-carboxylates were reacted with A- [3,5-bis(trifluoromethyl)-phenyl]methyl methylamine to yield carboxamides (01MIP12). [Pg.315]

Reaction of ethyl 7-bromo-8-fluoro-l-(2-bromo-l-methylethyl)-4-oxo-l,4-dihydroquinoline-3-carboxylate with MeNH2 yielded 10-bromo-A, 1, 3-trimethyl-7-oxo-2,3-dihydro-7//-pyrido[l,2,3-<7e]quinoxaline-3-carboxamide (OOMIPIO). [Pg.320]

Such direct cyclizations usually occur in basic media to afford quinoxaline A-oxides. For success, C2 in the ethyl group needs to be a carbonyl entity or to be suitably activated. The following examples illustrate this valuable route to such A-oxides (and thence to quinoxalines see Section 4.6.2.1). [Pg.6]

Dimethyl-1,5-benzodiazepine, formulated as its 3H tautomer (445), underwent vapor-phase pyrolysis (850°C, 0.02 mmHg, 15 min) to give a mixmre from which three quinoxalines were isolated 2,3-dimethyl- (446, R = Me) (7%), 2-ethyl-3-methyl- (446, R = Et) (10%), and 2-methyl-3-vinylquinoxa-line (447) (1%). ... [Pg.60]

Chloroquinoxaline with diethyl malonate, ethyl cyanoacetate, or malononitrile gave 2-(diethoxycarbonylmethyl)- (57), 2-(a-cyano-a-ethoxycarbonylmethyl)-(58, R = COaEt), or 2-(dicyanomethyl)quinoxaline (58, R = CN) [KOH,... [Pg.104]

Dimethylquinoxaline (147) gave 2-ethoxycarbonyl-2-hydroxy -methyl-2,3-dihydro-[l/ ]-pyrrolo[l,2-u]quinoxalin-10-ium bromide (148) (BrCH2CO-C02Et, AcEt, reflux, 3h, then 20°C, 12 h 72%) and thence successively ethyl 4-methylpyrrolo[l,2-fl]quinoxaline-2-carboxylate (149) (EtONa, EtOH, 20°C, 4h 93% note oxidation by loss of H2O), the uncharacterized quaternary salt (150) (as the first step but 6h 50%), and diethyl dipyr-rolo[l,2-fl 2, l -c]quinoxaline-2,ll-dicarboxylate (151) (KOH, H2O, reflux, 1 h 56%). ° " - ... [Pg.119]

Chloro-3-methylquinoxaline 4-oxide gave 3-chloro-2-quinoxalinecarbalde-hyde 1-oxide (172) (SeOi, PhH, reflux, h 72%) dioxane may be used as solvent for such oxidations yielding, for example, 3-amino-2-quinoxaline-carbaldehyde ethyl acetate may also be so used. [Pg.124]

Ethyl 3-dichloromethyl-2-quinoxalinecarboxylate 1,4-dioxide (292) gave pyri-dazino[4,5-/7]quinoxalin-l(2/i)-one (293) (H2NNH2-H20, EtOH, 0°C 20°C, 24 h 60% note the concomitant removal of the A(-oxide entities). ... [Pg.186]

Bis(bromomethyl)quinoxaline (296) gave either 6,8-dihydrofuro[3,4-g]qui-noxaline (297) (NaOH, H20-MeCN, BU4NHSO4, no further details 84%) or ethyl 7-isocyano-7,8-dihydro-6//-cyclopenta[g]quinoxaline-7-carboxylate (298) (Et02CCH2NC, K2CO3, BU4NHSO4, MeCN, no further details 38%) and thence the 7-amino ester (HCl-EtOH, no further details 90%). ... [Pg.187]

Chloro-2-(Af-methylhydrazino)quinoxaline 4-oxide (295) gave ethyl 7-chloro-1 -methyl- //-[ 1,3,4]oxadiazmo[5,6-Z7]qumoxaline-3-carboxylate (296) (Et02-CCOCl, pyridine, CHCI3, 5°C —> reflux, 2 h 81% mechanism discussed). ... [Pg.240]

The same substrate (25) aud ethyl 2-chloroacetoacetate gave an analogous product, ethyl 3-hydroxy-3-methyl-3,4-dihydro-2//-1,4-thiazino[2,3-h]qui-noxahne-2-carboxylate (27) (KOH, EtOH, 20°C, 3 h 58%), which underwent dehydration to ethyl 3-methyl-2H-1,4-thiazino[2,3-h]quinoxaline-2-carboxy-late (28) (HCl gas, EtOH, 20°C, 15 h 60% analogs likewise). ... [Pg.245]

Note These examples are extensions of the Friedlander quinoline synthesis. 3-Ammo-2-quinoxalinecarbaldehyde (183, R = H) and diethyl malonate (184) gave ethyl 2-oxo-l,2-dihydropyrido[2,3-fc]quinoxaline-3-carboxylate (185, R = H) (trace NaOH, trace H2O, EtOH, 10 min 60%). ... [Pg.293]

Af-Ethylhydrazino)quinoxaline 4-oxide (277, R = Et) and dimethyl acetylene-dicarboxylate gave dimethyl 1-ethyl-l,2-dihydropyridazino[3,4-/ ]quinoxa-line-3,4-dicarboxylate (278, R = Et) (EtOH, reflux, 3 h 77%) the 1-methyl homolog (278, R = Me) (70%) was made similarly. ... [Pg.310]

Ethyl 3-benzoyl-2-quinoxalinecarboxylate 1,4-dioxide (5) gave 2-quinoxaline-carboxylic acid 1,4-dioxide (6) (KOH, EtOH, 20°C, rapidly 58% note additional debenzoylation). " ... [Pg.319]

Thiocyanatoquinoxaline (67) and ethyl cyanoacetate gave 2-(a-cyano-a-ethoxycarbonylmethyl)quinoxaline (68) [NaH, (Me2N)3PO, 20°C, 2h 75%]. [Pg.329]

Ethyl 3-formyl-2-quinoxalinecarboxylate 1,4-dioxide (86) gave 2-phenylpyrida-zino[4,5-h]quinoxaline-l(277)-one (87) (excess PhNHNH2, EtOH, reflux, 2h ... [Pg.333]

Note The introduction of a passenger cyano group has been exemplified in earlier chapters. A single typical example is given here. 3-Chloro-2-quinoxalinecarbaldehyde (147) and ethyl cyanoacetate gave 2-chloro-3-(2-cyano-2-ethoxycarbonylvinyl)quinoxaline (148) (neat reactants,... [Pg.343]

See other pages where 4- Ethyl quinoxaline is mentioned: [Pg.356]    [Pg.411]    [Pg.17]    [Pg.141]    [Pg.162]    [Pg.182]    [Pg.835]    [Pg.18]    [Pg.240]    [Pg.318]    [Pg.74]    [Pg.166]    [Pg.183]    [Pg.186]    [Pg.194]    [Pg.223]    [Pg.230]    [Pg.309]    [Pg.328]   
See also in sourсe #XX -- [ Pg.308 ]



SEARCH



© 2024 chempedia.info