5-Hydroxy-2-methoxy-3-phenylpyrazine

Hydroxy-3-methoxy-5-phenylpyrazine refluxed with phosphoryl chloride formed 2-chloro-3-methoxy-5-phenylpyrazine (365a). 

Amino-5-bromo-3-carbamoylpyrazine heated with trifluoroacetamide and sodium ethoxide (or butoxide) gave 6-ethoxy(or butoxy)-4-hydroxy-2-trifluoro-methylpteridine (49) (987) and 2-chloro-3-pyridiniopyrazine chloride with methoxide ion gave 2,3-dimethoxypyrazine (765). 2-Amino-3-bromo-5-phenyl-pyrazine with sodium methoxide in methanol at 134° for 8 hours formed 2-amino-3-methoxy-5-phenylpyrazine (365a) and 3-bromo-2-hydroxy-5-phenylpyrazine similarly treated gave 2-hydroxy-3-methoxy-5-phenylpyrazine (365a). 

Dimethylamino-7V-hydroxy-2-pyrazinecarboxamide 6-Dimethylamino-7V-hydroxy-2-pyrazinecarboxamidine 2-Dimethylamino-5-iodopyrazine 2-Dimethylamino-6-iodopyrazine 2-Dimethylamino-5-iodopyrazine 4-oxide 2-Dimethylamino-3-isobutylpyrazine 2-Dimethylamino-6-isobutylpyrazine 2-Dimethylamino-5-methoxy-3,6-dimethylpyrazine 2-Dimethylaminomethyl-3,6-bismethylthiopyrazine 2-Dimethylamino-6-methyl-5-phenylpyrazine 4-oxide 2-Dimethylamino-3-methylpyrazine 2-Dimethylamino-6-methylpyrazine 2-Dimethylamino-3-methylpyrazine 4-oxide Dimethyl 5-amino-6-oxo-1,6-dihydro-2,3-pyrazinedicarboxylate 2-Dimethylamino-5-phenylpyrazine 2-(3-Dimethylaminopropyl)-6-methylpyrazine... 

Methoxypyrazines (31) have been prepared by diazomethane methylation of 2-hydroxy-3-isobutylpyrazine (60, 311, 367), 2-hydroxy-3-isopropylpyrazine (59, 367), 2-hydroxy-3-propyl(ethyl or hexyl)pyrazine (367), 3-hydroxy-2-isobutyl-5(and 6)methylpyrazine and 2-hydroxy-3-isobutyl-5,6-dimethylpyrazine (368), 2,3-dihydroxypyrazine (832), 2-hydroxy-5-methoxy- and 2,5-dihydroxy-3,6-diphenyl-pyrazine (832), 2-hydroxy-6-methoxy(and benzyloxy)pyrazine (832), 2,6-dihydroxy-3,5-diphenylpyrazine (873), 2,3,5-trifluoro-6-hydroxypyrazine (851), 2-chloro-6-hydroxy-3,5-diphenylpyrazine (873), 2-chloro-6-hydroxy-5-methyl-3-phenylpyrazine (873), 2-chloro-6-hydroxy-3-methyl-5-phenylpyrazine (873), 5,6-dichloro-1 -cyclohexyl-34iydroxy-2-oxo-l, 2-dihydropyrazine (853), 2-chloro-5-hydroxy-3-methoxy-6-methoxycarbonylpyrazine (881), 2-(4 -amino-3, 5 -dibromo-phenylsulfonamido)-3Tiydroxy-6-methoxypyrazine (881), 2-amino-3-hydroxy-... 

A 2-amino-5-substituted-pyrazine refluxed with p-toluenethiol, 2-methoxy-ethanol, and 2-amino-6-formyl-4-hydroxypteridine followed by heating with acetic anhydride gave the 2-amino-4-hydroxy-6-[A -(5 -substituted-pyrazin-2 -yl)-acetamidomethyl]pteridine (34) (1244). 2-Amino-5-phenylpyrazine with isobutyral-dehyde in ether at room temperature gave 2-(3-isopropyl-6, 6-dimethyl-5, 6-dihydro-l, 2, 4 -trioxin-5 -yl)aniino-5-phenylpyrazine (35) (1245). 

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