Synthesis of Pyranobenzopyranopyridines and Benzodipyran Derivatives

نویسندگان

  • O. H. Hishmat
  • A. H. Abd el-Rahman
چکیده

6-Formyl-7-hydroxy-5-methoxy-2-methylchromone on bromination yields the 8-bromo deriva­ tive or the 8-bromo-6-formyl-5,7-dihydroxy derivative depending on the reaction condition. Cyclization of both leads to the corresponding 3-acetyl-, 3-benzoyl-, 3-carboxamido-, 3-carbethoxybenzodipyran derivatives. The 3-acetylbenzodipyran derivative when treated with ethyl acetoacetate or ethyl cyanoacetate in the presence of ammonium acetate yields the corresponding dihydropyranobenzopyranopyridine dione or the dihydropyranobenzopyranopyridine trione. The reaction of the 3-acetyl derivative with cyanoacetamide in the presence of ammonium acetate affords the substituted pyranobenzopyranopyridine dione. The 3-acetyl derivative undergoes self condensation to form the substituted benzopyranobenzopyran derivative.

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تاریخ انتشار 2012