By Hydrolysis of Iminoethers and Iminothioethers

Iminoethers have been hydrolyzed to esters and iminothioethers to thioesters. Some examples follow 2-cyano-3-(C-ethoxy-C-iminomethyl)-5,6-dimethylpyrazine [2-cyano-3-(C-ethoxyformidoyl)-5,6-dimethylpyrazine] (26) in boiling water gave 

2- cyano-3-ethoxycarbonyl-5,6-dimethylpyrazine (1044) 2-amino-3-(C-ethoxy-C-iminomethyl) 5-trifluoromethylpyrazine [from 2-amino-3-carbamoyl-5-trifluoro-methylpyrazine with Meerwein s reagent (1357), triethyloxonium fluoroborate (Et30Bp4)] in dilute acid gave 2-amino-3-ethoxycarbonyl-5-trifluoromethyl-pyrazine (802) 2-amino-5-cyano-3-(C-imino-C-methoxymethyl)-6-methoxypyrazine (prepared from salts of l,l,3,3-tetracyano-2-azapropenide with sodium methoxide in methanol) with 2N hydrochloric acid in acetonitrile at 60° gave 2-amino-5-cyano.6-methoxy-3-methoxycarbonylpyrazine (but with dry hydrogen chloride in methanol it gave 2-amino-3-carbamoyl-5-cyano.6-methoxypyrazine)(484) 2-amino- 

3- (C-imino-C-methylthiomethyl)pyrazine refluxed in N hydrochloric acid gave 2-amino-3-(methylthio)carbonylpyrazine (1075) and 2-methoxy-6-(C-imino-C-methoxymethyOpyrazine (from 2 hloro-6-cyanopyrazine with one equivalent of sodium methoxide) acidified with hydrochloric acid gave 2-methoxy-6-methoxycarbonylpyrazine (986). 

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