2-Chloro-5-methoxy-3,6-dimethylpyrazine

Many chlorinations of pyrazines have been achieved with sulfuryl chloride. A series of monoalkylpyrazines has been chlorinated specifically in the 3-position with sulfuryl chloride in the presence of 7V,A -dimethylformamide for example, 2 -butylpyrazine in MjV-dimethylformamide with sulfuryl chloride at 45° gave 2iS-butyl-3-chloropyrazine. The nucleus of 2,6-dialkylpyrazines was also readily chlorinated (687, 693). 2,6-Dimethylpyrazine and sulfuryl chloride in A. A -dimethyl-formamide gave 2-chloro-3,5-dimethylpyrazine (687, 844), and 3-methoxy-2,5-dimethylpyrazine gave 2-chloro-5-methoxy-3,6-dimethylpyrazine (844). 

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-... 

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