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5- Methylquinoxaline 1-oxide

Methylquinoxaline 4-oxide (264) selectively from 2-methylquinoxaline 1,4-dioxide (265) (ascorbic acid, H2O, 90°C, 5 h 58% homologs likewise) the natural amino acids in foods can also reduce such quinoxaline N-... [Pg.234]

Acetyl-3-methylquinoxaline 1-oxide (206) gave 2-methylquinoxaline 4-oxide (207) [HN(CH2CH2)20, MeCN, reflux, 24 h 30%]. ... [Pg.354]

Quinoxaline /V-oxides undergo various rearrangements. Ring contraction to benzimidazoles is exemplified by 2-methylquinoxaline 4-oxide... [Pg.417]

Peracetic acid oxidation of l-methylquinoxalin-2-one (42) at 55°C gives l-methylquinoxaline-2,3-dione (43) in moderate yield, and similar treatment of l,3-dimethylquinoxalin-2-one (44) yields a small quantity of the 4-oxide, An improved yield of (43) is obtained by... [Pg.216]

Oxidation of 4-methylquinoxalin-3-one 2-carboxy-fV -methylamlide (45) with hydrogen peroxide and acetic acid furnishes the 1-oxide but, on removal of either or both of the fV-raethyl groups (giving 46, 47, or 48), oxidation with hydrogen peroxide or with peracetic or perbenzoic acid results in the removal of the carboxyamide groups and the formation of a quinoxaline-2,3-dione. ... [Pg.217]

Chromic acid oxidation of hydroxyiminomalon-bis-AT -methylanilide (93) gives 4-methylquinoxalin-3-one-2-carboxy-A -methylanilide 1-oxide (94) by a process involving AT -oxidation and dehydrative ring closure. ... [Pg.235]

Reaction of nitromalon-bis-A -methylanilide (105) with sulfuric acid gives A -methylisatin- -oxime (107) and not 4-methylquinoxalin-3-one 1-oxide (108) as originally suggested. This transformation may involve a Beckmann-type rearrangement of the protonated aci-nitro compound (106) prior to dehydrative ring closure. ... [Pg.238]

The somewhat analogous substrate, p-methoxy-A-(2-nitroprop-l-enyl)aniline (15), afforded 6-methoxy-3-methylquinoxaline 4-oxide (16) (98% H2SO4 %). ... [Pg.3]

Benzoxadiazole 1-oxide (473) gave 2-acetyl-3-methylquinoxaline 1,4-dioxide (472) (AC2CH2, NaOH, EtOH, 55°C, 90 min, then 20°C, 12 h 54% or AC2CH2 on Si02 gel, 20°C, 7 days 58%), 2-benzoyl-3-methylquinoxaline 1,4-dioxide (474) (BZCH2AC on 3A molecular sieve,... [Pg.63]

BzCH2C(=0)CH2Ph, neat EtjN, 20°C, 24 h 21%) ° 5,6-Difluoro-2,l,3-benzoxadiazole 1-oxide (476) gave 2-acetyl-6,7-difluoro-3-methylquinoxaline 1,4-dioxide (477) (AC2CH2, neat Et3N, 5°C, 1 h, then 20°C, 1 h 72% analogs likewise). ° = ... [Pg.64]

Benzoxadiazole 1-oxide (481) with 3-acetyltetrahydro-2-furanone (2-acetyl-butyrolactone 482) gave 2-(2-hydroxyethyl)-3-methylquinoxaline 1,4-diox-ide (483) (KOH, MeOH-HaO, 20°C, 24 h 50%) but with 2-acetylacetaldehyde dimethyl acetal (484), in the presence of morpholine as base, it gave 2-(2-morpholinovinyl)quinoxaline 1,4-dioxide (485) (PhH, reflux, water separation, 9 h 47%) ... [Pg.65]

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]

Chloro-3-methylquinoxaline gave only 2-chloro-4-methylquinoxaline 4-oxide (241) (m-ClC6H4C03H, CHCI3, 20°C, 6 h 82%). °... [Pg.228]

Acetyl-3-methylquinoxaline 4-oxide (218, X = 0) gave 2-methyl-3-(l-tosyl-hydrazonoethyl)quinoxaline 1-oxide (218, X = NNHTs) (TSNHNH2, MeOH,... [Pg.298]

Azido-3-methylquinoxaline 1,4-dioxide (293) underwent thermolytic ring contraction with loss of N2 to give a separable mixture of 2-methyl-3//-benzimidazole-2-carbonitrile 1,3-dioxide (294) and its rearrangement product, 3-methyl-3//-2,l,4-benzoxadiazine-3-carbonitrile 4-oxide (295) (PhH, reflux, 10 min 46% and 41%, respectively) the latter product (295) was also obtained from the benzimidazole (294) (PhH, reflux, 30 min 76%) or from the quinoxaline (293) (PhMe, 90°C, 30 min 94%). ... [Pg.313]

Ethyl 3-methyl-2-quinoxalinecarboxylate 1-oxide Ethyl 3-methyl-2-quinoxalinecarboxylate 4-oxide 2-Ethyl-3-methylquinoxaline 1,4-dioxide... [Pg.407]

Methyl-2-quinoxalinamine 8-Methyl-6-quinoxalinamine 3-Methyl-2-quinoxalinamine 1,4-dioxide 3-Methyl-2-quinoxalinamine 4-oxide 2-Methylquinoxaline... [Pg.424]

See other pages where 5- Methylquinoxaline 1-oxide is mentioned: [Pg.192]    [Pg.192]    [Pg.425]    [Pg.31]    [Pg.169]    [Pg.204]    [Pg.235]    [Pg.237]    [Pg.447]    [Pg.164]    [Pg.192]    [Pg.361]    [Pg.364]    [Pg.364]    [Pg.369]    [Pg.375]    [Pg.377]    [Pg.378]    [Pg.378]    [Pg.383]    [Pg.384]    [Pg.384]    [Pg.384]    [Pg.384]    [Pg.404]    [Pg.407]    [Pg.413]    [Pg.415]    [Pg.415]   
See also in sourсe #XX -- [ Pg.234 , Pg.354 ]

See also in sourсe #XX -- [ Pg.234 , Pg.354 ]



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2- Methylquinoxalines

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