6-Chloro-2-pyrazinecarboxylic acid

Chloro-2-pyrazinecarboxylic acid gave 3-oxo-3,4-dihydro-2-pyrazinecar-boxylic acid (0.5 M NaOH, reflux, 1 h >95%).1271... [Pg.159]

Chloro-2-pyrazinecarboxamide 4-oxide 6-Chloro-2-pyrazinecarboxamidrazone 3-Chloro-2-pyrazinecarboxylic acid... [Pg.394]

The most convenient synthesis of halogenopyrazines and -quinoxalines is by halogenation of pyrazinones and quinoxalinones with phosphoryl or other acid halides for example, 5-hydroxy-2-pyrazinecarboxylic acid, rather than 5(477)-pyrazinone-2-carboxylic acid, is chlorinated with phosphorus pentachloride/phosphoryl chloride to afford a 63% yield of 5-chloro-2-pyrazinecarbonyl chloride <1994SL814>. Sato and Narita provided an improved synthesis of various halogenopyrazines in which 2(l//)-pyrazinones were activated with chlorotrimethylsilane to give silyl ethers (Section 8.03.7.3). This procedure is most effective for synthesis of bromopyrazines whose overall yields are 62-81% <1999JHC783>. Bromopyrazine is directly prepared by treatment of 2-(l//)-pyrazinone with phosphoryl... [Pg.317]

Pyrazinecarboxylic acid underwent microbiological hydroxylation to give 3-oxo-3,4-dihydro- (36, R = H) (Alcaligenes eutrophus 70%), 5-oxo-4, 5-dihydro- (37) (.Pseudomonas acidovorans 96%), or 6-oxo-l,6-dihydro-2-pyrazinecarboxylic acid (38) (Alcaligenes faecalis 85%) 1091 Similar procedures afforded 5-chloro-3-oxo-3,4-dihydro-2-pyrazinecarboxylic acid (Alcaligenes eutrophus 50%) and 5-oxo-4,5-dihydro-2-pyrazinecarbonitrile (Agrobacterium sp 78%).1091... [Pg.195]

Methyl 6-chloro-5-(4-methylpiperazin-l-yl)-2-pyrazinecarboxylate (8, R = Me) gave 6-chloro-5-(4-methylpiperazin-l-yl)-2-pyrazinecarboxylic acid (8, R = H) (NaOH, EtOH—112(), 20°C, 12 h 96%, isolated as hydrochloride).645... [Pg.300]

Chloro-2-pyrazinecarboxyhc acid (28, R = Cl) gave 6-chloro-2-pyrazinecar-bonyl chloride (29, R = Cl) (SOCl2, PhH, reflux, 90 min 73%) 505 and 6-phenyl-2-pyrazinecarboxylic acid (28, R = Ph) gave 6-phenyl-2-pyrazinecarbonyl chloride (29, R = Ph) (neat SOCl2, reflux, 2 h uncharacterized product).1015... [Pg.304]

Diamino-6-chloro-2-pyrazinecarboxylic acid (31, R = H) gave cyanomethyl 3,5-diamino-6-chloro-2-pyrazinecarboxylate (31, R = CH2CN) (C1CH2CN, Et3N, Me2NCHO, 20°C, 24 h 90%).1317... [Pg.304]

Acetamido-6-bromo-2-pyrazinecarboxamide 6-Acetamido-5-bromo-2-pyrazinecarboxylic acid 2-Acetamido-5-chloro-3-guanidinocarbonylpyrazine 2-Acetamido-5,6-dichloro-3-nitropyrazine... [Pg.351]

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

Chloro-5-methylpyrazine 2-Chloro-6-methylpyrazine 6-Chloro-A,-methyl-2-pyrazinecarboxamidine 6-Chloro-5-methyl-2-pyrazinecarboxylic acid 5-Chloro-6-methyl-2-pyrazinecarboxylic acid 1-oxide... [Pg.393]

Many amides have been prepared from pyrazinecarboxylic acid chlorides some are listed below with the relevant amines and references 2-chlorocarbonyl [MeNHj/ EtOAc (138) Me NH/EtOAc (138) BujNH etc/EtOAc (138) aniline/EtOAc (138, 1335) other aromatic and heterocyclic amines/EtOAc (138) sulfanilamide/ pyridine (1336) p-(2 -aminoethyl)benzenesulfonamide (1385) p-anisidine/benzene (1334) 4-hydroxypiperidine/benzene chloroform (1386) morpholine/DMF/20° (1387) 2-aminopyrimidine/benzene (1388) glycine/NaOH/ether (1201, cf. 1333, 1360)] 2-chlorocarbonyl-5-methyl [MeNHj/benzene (1337) MejNH/benzene (1337) 4-phenylpiperazine or diethanolamine/benzene-chloroform (1386) 2-chlorocarbonyl-3-phenyl (6-aminopenicillanic acid) (1024) 2-chloro-3-chloro-carbonyl (morpholine/benzene) (838) 2-chloro-5-chlorocarbonyl (NH4OH) (839) 2-chloro-6-chlorocarbonyl (Et2NH/benzene) (870, 1389) 2-chlorocarbonyl-5-hydroxy (aniline/benzene) (1055) 2-chlorocarbonyl-3-methoxy (morpholine/ benzene) (867) 2-chlorocarbonyl-5-methoxy (morpholine/benzene-chloroform) (1386) and 2-(l -chlorocarbonylethyI) (morpholine/benzene) (364). [Pg.275]

Diamino-6-chloro-2-pyrazinecarboxylic acid (31, R = H) gave cyanomethyl... [Pg.304]

Dianiino-6-cliloro-2-pyrazinecarboxylic acid (39, R = OH) gave 3,5-di-ammo-6-chloro-Af-phenyl-2-pyrazinecarboxaniide (39, R = NHPh) [PhNH, ethyl 2-ethoxy-l,2-dihydro-l-quinolinecarboxylate, MC2SO, 30°C, 24 h 84% probably via a mixed anhydride] ... [Pg.306]

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