Preparation of A-Alkylpyrazinium Salts

The quatemization of pyrazines has been done under a wide variety of conditions, as illustrated in Section 3.1.3 and in the following recent examples  

Dimethyl 2,3-pyrazinedicarboxylate gave l-ethyl-2,3-dimethoxycarbonylpyrazinium tetrafluoroborate (347) (1 11 )liD. CICH2CH2CI, reflux, 2 h SO Fi methyl 2-pyrazinecarboxylate gave 3-methoxycarbonyl-l-methylpyrazinium iodide (348) 

2-Methylpyrazine 1-oxide gave 1,3-dimethylpyrazinium iodide 4-oxide (351) (Mel, AcMe, or EtOH , sealed, 100°C, 4 h 95%) homologues were made likewise and similar treannent of pyrazine 1,4-dioxide gave a separable ( ) mixture of 1-methylpyrazinium iodide and its 4-oxide in approximately equal amounts.  

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