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[摘要]：Hydroxylamine hydrochloride reacts readily with (5-amino-1-aryl-1H-imidazol-4-yl)iminoacetonitriles to furnish 5-amino-1-aryl-N-hydroxy-1H-imidazole-4-carboxamidines. When a mixture of 5-amino-1-aryl-N-hydroxy-1H-imidazole-4-carboxamidine and excess of triethyl orthoesters is reacted at room temperature novel purin-6-one oximes are obtained in moderate yields. Further, reaction of formamidines and ethyl acetoacetate with DBU afforded 6-carbamoylpurines. X-Ray analysis carried out on 9-(4-methoxyphenyl)-2-methyl-9H-purine-6-carboxamide monohydrate confirmed its structure. Diazotization of [5-amino-1-(4-methoxyphenyl)-1H-imidazol-4-yl]iminoacetonitrile in the presence of an excess of sodium nitrite and concentrated HCl gave 4-carboxy-5-chloro-1-(4-methoxyphenyl)imidazolidinium chloride via nucleophilic aromatic substitution reaction. However, (1-aryl-5-hydroxy-1H-imidazol-4-yl)iminoacetonitrile is obtained as product when (5-amino-1-aryl-1H-imidazol-4-yl)iminoacetonitriles (Ar = 4-MeC6H4 and Ar = 4-ClC6H4) were the reactants. The structure of 4-carboxy-5-chloro-1-(4-methoxyphenyl)imidazolidinium chloride was also established by X-ray analysis. |
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