Replacement of Amino by Hydroxy and Alkoxy Groups

The conversions of amino to hydroxy groups have been described in Sections VI.IC and VI.9A(5), and to alkoxy groups in Section VI.3C. 

The replacement of amino groups by fluoro, bromo, and iodo substituents has been described in Section V.IH (882, 884), Section V.IK (798-800, 807, 890-892) and Section V.ll (887), respectively and of hydrazino groups by chloro and bromo substituents in Section V.l J (851,888). 

When 2-amino-5-chloro-3-methoxycarbonylpyrazine was refluxed with aniline and concentrated hydrochloric acid in acetone for 16 hours, the anil, 5-anilino-2-isopropylideneamino-3-methoxycarbonylpyrazine (22) was formed (432, 778, 780), and 2-amino-5-chloro-3-methoxycarbonyl-6-(l -methylhydrazino)pyrazine with benzaldehyde in ethanol gave 2-amino-6-(2 -benzylidene-r-methylhydrazino)-5-chloro-3-methylcarbonylpyrazine (23) (809). A series of hydrazones has been prepared by refluxing equimolar quantities of 2-hydrazinopyrazine and carbonyl compounds in the presence of catalytic quantities of p-toluenesulfonic acid in benzene (1195). Other preparations of similar hydrazones have been described (1196). 

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