3-Amino-2-pyrazinecarboxylic acid

Azirines are dimerized under various conditions to dihydropyrazines or their dehydrogenated products, namely pyrazines (Section 8.03.9.5). Quinoxalines are oxidized with potassium permanganate to afford 2,3-pyrazinedicarboxylic acids, and pteridines are hydrolyzed to give 3-amino-2-pyrazinecarboxylic acid derivatives. Condensation of 3,4-diamino-l,2,5-thiadiazole 176 with a-diketones produces l,2,5-thiadiazolo[3,4- Jpyrazines 177, which are reduced to provide 2,3-diaminopyrazines 178 (Scheme 51) <1997JCM250>. [Pg.313]

Pyrazinecarboxylic acid (32, R = H) gave methyl 2-pyrazinecarboxylate (32, R = Me) (MeOH, trace H2S04, reflux, 48 h 85-95%)236,460 or the corresponding ethyl ester (82, R = Et) (EtOH, H2S04, reflux, 7 h 74%) 896 3-amino-2-pyrazinecarboxylic acid gave methyl 3-amino-2-pyrazinecarboxy-late (MeOH, H2S04, 65°C, 2 h 57%).332... [Pg.304]

Amino-2-pyrazinecarboxylic acid (40, R = H) gave 3-amino-A1-(methoxy-carbonylmethyl)-2-pyrazinecarboxamide (40, R = NHCH2C02Me) [H2N-CH2C02Me, (EtO)2POCN, MeOCH2CH2OMe, Et3N, 0 - 20°C, 2 h 76-78%].1331,1652... [Pg.306]

Amino-2-pyrazinecarboxamide 3-Amino-2-pyrazinecarboxamide methyloxime 3-Amino-2-pyrazinecarboxamide 1-oxide 5-Amino-2-pyrazinecarboxamide 4-oxide 3-Amino-2-pyrazinecarboxamide oxime 3-Amino-2-pyrazinecarboxamidrazone 3-Amino-2-pyrazinecarboxylic acid... [Pg.365]

This section covers primary, secondary, tertiary, and quaternary aminopyrazines (both nuclear and extranuclear) but not (functionally substituted amino)pyrazines such as hydrazino-, hydroxyamino-, or azidopyrazines. General discussions have appeared on the spectra of 2-pyrazinamine, 55 5 the proton-sponge properties of 2,3,5,6-tetra(pyridin-2-yl)pyrazine in relation to its fine structure, the fluorescene properties of 3,6-diamino-2,5-pyrazinedicarboxylic acid derivatives in relation to their fine structures, 1 46,1659 jjjg basic properties of aminopyrazines and other such azines in relation to their electronic struc-tures, and the fine structures of 3-amino-2-pyrazinecarboxylic acid and... [Pg.265]

Condensation of 1,2-diaminopropane and 2,3-dioxobutane similarly gives 5,6-dihydro-2,3,5-trimethylpyrazine which is oxidized to the corresponding pyrazine in 58% yield by treatment with potassium hydroxide pellets.111 Hydroxypyrazines are very conveniently prepared from a,j8-dicarbonyl compounds and a-amino acid amides [Eq. (1)],30,112 and pyrazinecarboxylic acids have been prepared by condensation of an a,)5-diketone with an a,/ -diaminocarboxylic acid, followed by oxidation (Scheme 2). Thus, condensation of benzil and... [Pg.113]

The greater stability of the pyrazine ring to oxidation compared with that of benzene enables pyrazinecarboxylic acids to be prepared by permanganate oxidation of either quinoxalines or phenazines. The pyrazine ring is more stable than the pyrimidine ring to acid and alkaline hydrolysis. Thus, pteridine is converted into 2-amino-3-formylpyrazine on treatment with dilute sulfuric acid and N-(3-formyl-2-pyrazinyl)formamidine oxime on treatment with sodium carbonate and hydroxylamine (Scheme 11).136 Aminopyrazines and... [Pg.119]

Amino-5,6-dichloro-2-pyrazinecarboxylic acid (1) gave 5,6-dichloro-3-nitro-2-pyrazinamine (2) (H2S04—HN03, 15 —> 20°C, 4 h 46% C02 f during the reaction).607,1313... [Pg.259]

Methyl 3-amino-6-phenyl-2-pyrazinecarboxylate (7, R = Me) gave 3-amino-6-phenyl-2-pyrazinecarboxylic acid (7, R = H) (NaOH, MeOH—II20, 20°C, 1 h 88%).599... [Pg.300]

Amino-5-phenyl-2-pyrazinecarbaldehyde (19, R = H) gave 3-amino-5-phenyl-2-pyrazinecarboxylic acid (19, R = OH) (KMn04, HzO, 20°C, 1 h 28%).1385... [Pg.302]

Amino-5-azido-2,6-pyrazinedicarbonitrile 3-Amino-5-benzoyl-6-bromo-2-pyrazinecarbonitrile 3-Amino-5-benzoyl-2-pyrazinecarbonitrile 3-Amino-5-benzoyl-2-pyrazinecarboxamide 3-Amino-6-benzylamino-2-pyrazinecarboxylic acid 6-Amino-5-benzyl-3-methyl-2(177)-pyrazinone 3-Amino-6-benzylsulfinyl-2-pyrazinecarboxylic acid 3-Amino-6-benzylthio-... [Pg.356]

Amino-6-chloro-5-(prop-2-ynylamino)-2-pyrazinecarboxylic acid — (H 426)... [Pg.359]

Amino-6-chloro-2-pyrazinecarboxylic acid 3-Amino-6-chloro-2-pyrazinecarboxylic acid... [Pg.360]

Amino-6-cyclohexyl-2-pyrazinecarboxamide 3-Amino-5-cyclohexyl-2-pyrazinecarboxylic acid 3-Amino-6-cyclohexyl-2-pyrazinecarboxylic acid 3-Amino-/V-cyclopentyl-2-pyrazinecarboxamide 3-Amino-6-cyclopropyl-2-pyrazinecarbonitrile 3-Amino-6-cyclopropyl-2-pyrazinecarboxamide 3-Amino-6-cyclopropyl-2-pyrazinecarboxylic acid 3-Amino-5,6-dichloro-2-pyrazinecarbaldehyde 3-Amino-5,6-dichloro-2-pyrazinecarbonitrile 3-Amino-5,6-dichloro-2-pyrazinecarboxamide 3-Aniino-5,6-dichloro-2-pyrazinecarboxylic add 3-Amino-6-diethylaminomethyl-2-pyrazinecarbonitrile 3-Amino-5-diethylamino-2,6-pyrazinedicarbonitrile 5-Amino-3-dimethylamino-6-nitro-2-pyrazinecarbonitrile 3-Amino-5-dimethylamino-6-phenyl-2-pyrazinecarbohydrazide... [Pg.360]

Amino-5-dimethylamino-2-pyrazinecarboxylic acid 3-Amino-6-dimethylamino-2-pyrazinecarboxylic acid 3-Amino-5-dimethylamino-2,6-pyrazinedicarbonitrile 5-Amino-6-dimethylamino-2,3-pyrazinedicarboxamide 3- Amino-6-(3,3-dimethylbut-1 -ynyl)-2-pyrazinecarbonitrile 3-Amino-/V, /V -dimethyl-2-pyrazine-carbohydrazide... [Pg.361]

Amino-5,6-dimethyl-2-pyrazinecarbohydrazide 3-Amino-5, /V-dimethyl-2-pyrazinecarboxamide 3-Amino-5,6-dimethyl-2-pyrazinecarboxamide 3-Amino-5,6-dimethyl-2-pyrazinecarboxylic acid 3 Anniio-5.6 dimelliyi 2(1//) pyTn/iiK thione... [Pg.361]

Amino-5,6-diphenyl-2-pyrazinecarbothioamide 3-Amino-5,6-diphenyl-2-pyrazinecarboxamide 3-Amino-5,6-diphenyl-2-pyrazinecarboxylic acid 3-Amino-5,6-diphenyl-2(177)-pyrazinethione 1 - Amino- 3,5 - dipheny lpy razinium (+ anion)... [Pg.361]

Amino-6-ethyl-2-pyrazinecarboxamide 3-Amino-6-ethyl-2-pyrazinecarboxylic acid 3-Amino-5-formyl-2-pyrazinecarbonitrile... [Pg.362]

Amino-2-pyrazinecarboxylic acid 4-oxide 3-Amino-2,6-pyrazinedicarbonitrile... [Pg.366]

Methylamino-6-methylcarbamoyl-2-pyrazinecarboxylic acid Methyl 3-amino-5-methyl-6-phenyl-2-pyrazinecarboxylate Methyl 3-amino-6-methyl-5-phenyl-2-pyrazinecarboxylate 3-Methylaminomethyl-2-pyrazinamine Methyl 3-amino-5-methyl-2-pyrazinecarboxylate Methyl 3-amino-6-methyl-2-pyrazinecarboxylate Methyl 3-amino-5-methylsulfinyl-2-pyrazinecarboxylate... [Pg.441]

Methyl 5-amino-2-pyrazinecarboxylate Methyl 6-amino-2-pyrazinecarboxylate Methyl 3-amino-2-pyrazinecarboxylate 4-oxide 3-Methylamino-2-pyrazinecarboxylic acid 6-Methylamino-2-pyrazinecarboxylic acid 2-Methylaminopyrazine 1-oxide 2-Methylaminopyrazine 4-oxide Methyl 6-anilino-3-isopropylideneamino-2-pyrazinecarboxylate Methyl 3-azido-2-pyrazinecarboxylate... [Pg.442]

Phenylpteridine (117) gave 3-ethyliminomethyl-6-phenyl-2-pyrazinamine (119) (neat EtNH2, 20°C, 4 h 78% via the adduct (118)] or a separable mixture of 4-ethylamino-7-phenylpteridine (120) and 3-amino-5-phenyl-2-pyrazinecarbaldehyde (121) [neat EtNH, KMnO4 (1 mol), 17°C, 5 h 26 and 38%, respectively, after separation the second, presumably via the Schiff base (119)] the aldehyde (121) was oxidized further to 3-ainino-5-phenyl-2-pyrazinecarboxylic acid (122) (KMnO4, H,O, 20°C, 1 h 28%). ... [Pg.65]

Big Chemical Encyclopedia

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