Presence of Amino and Carboxy Groups

Bromination of 2-amino-3-methoxycarbonylpyrazine in acetic acid gave 2-amino-5-bromo-3-methoxycarbonylpyrazine (787, 798) and the 2-methylamino analogue 

2- amino-5-bromo-3-carboxypyrazine, and 2-amino-5-bromo-3-methoxycarbonyl-pyrazine with bromine in aqueous hydrobromic acid (806, 807). 

3- cyanopyrazine (792, 808) and bromination of 3,5-diamino-2-methoxycarbonyl-pyrazine and 3-amino-5-methoxy-2-methoxycarbonylpyrazine in acetic acid gave 2,6-diamino-3-bromo-5-methoxycarbonylpyrazine (780, 781, 809) and 2-amino-5-bromo-6-methoxy-3-methoxycarbonylpyrazine (790), respectively. 

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