The Reactions of Diaminomaleonitrile with Isocyanates and Either Aldehydes or Ketones Revisited
作者:Brian L. Booth、Alice M. Dias、M. Fernanda Proença、Magdi E. A. Zaki
DOI:10.1021/jo010595w
日期:2001.12.1
urea derivatives of diaminomaleonitrile 2 with aldehydes or ketones in the presence of triethylamine has established that the products of these reactions are not pyrimidino[5,4-d]pyrimidines 9 as previously reported, but 8-oxo-6-carboxamido-1,2-dihydropurines 12, which are oxidized rapidly in air to the corresponding 6-carboxamidopurines 13. Similarly, the reaction of Schiff base derivatives of DAMN
在三乙胺存在下对二氨基马来腈2的尿素衍生物与醛或酮的反应进行的重新研究已确定,这些反应的产物不是以前报道的嘧啶并[5,4-d]嘧啶9,而是8-oxo-6 -甲酰胺基1,2-二氢嘌呤12,在空气中迅速氧化为相应的6-甲酰胺嘌呤13。类似地,在三乙胺的存在下,DAMN 5的席夫碱衍生物与异氰酸酯反应生成取代的2-氧代咪唑20和而不是先前要求保护的嘧啶衍生物8。化合物20在溶液中环化并且容易被氧化成8-氧代嘌呤-6-腈22,其在进一步水解时得到相同的8-氧代嘌呤-6-羧酰胺13。