3-Amino-5-chloro-2-methoxypyrazine

Q-(p-Toluenesulfonyloxyiinino)malononitrile (104), when treated with malono-nitrile in basic conditions, has been shown to give salts of l,l,3,3-tetracyano-2-azapropenide (105), which with concentrated sulfuric acid in methanol gave 2-amino-3,5-dicyano-6-methoxypyrazine (106) (484) and with hydrochloric acid in acetone gave 2-amino-6-chloro-3,5-dicyanopyrazine (485, 486). Catalytic cyclization of 2-(2 -aminobutylamino)butanol with Raney nickel has been found to give a mixture of 2,5-diethylpiperazine (25% yield) and 2,5-diethylpyrazine (8%) (487). 

Chloro-3-morpholinopyrazine treated with allyl alcohol followed by bromination in the presence of water has been shown to give 5-bromo-2-(3 -bromo-2-hydroxypropoxy)-3-morpholinopyrazine (813), and bromination of 2-amino[or 2-(p-toluenesulfonamido)]-3-methoxypyrazine with a mixture of potassium bromide and bromate in 6N sulfuric acid gave 2-amino-[or 2-(p-toluenesulfonamido)]-5-bromo-3-methoxypyrazine (814). The bromination (814) of 2-methoxy-3-sulfanilamidopyrazine in methanol was anomalous (815,816) [see Section 5D(2)]. 

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-... 

Dimethoxycarbonylpyrazine heated with hydrazine hydrate in ethanol gave some 5,8-dihydroxypyrazino[2,3-with hydrazines (and amines) has been described in Section 2C(2)(a) (961,1330, 1331). An analogous active ester was prepared from 2-amino-3-carboxy-5-chloro-6-methoxypyrazine and with hydrazine in tetrahydrofuran gave 2-amino-5-chloro-... 

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