A ONE-POT SYNTHESIS OF PYRAZOLO [3,4-b][1,4]OXAZINES
作者:M. A. Raslan、F. M. Abd El-Latif、H. H. Otto、K. U. Sadek
DOI:10.1080/00304940009355925
日期:2000.6
knowledge, only a few reports for the synthesis of pyrazolo[3,4-b] [ 1,410xazines have been described' and most of them involve many steps or give only poor to moderate yields.2 In connection with our interest in the synthesis of condensed azines7 ' from available laboratory materials, we report here a new efficient and simple route for the synthesis of pyrazolo[3,4-b][ I ,410xazines. Thus, treatment of
Synthesis of Various Pyrazolo[4′,3′ : 5,6]pyrano[3,2-<i>e</i>] [1,2,4]triazolo[1,5-<i>c</i>]pyrimidines and Pyrazolo[4″,3″ : 5′,6′]pyrano[2′,3′ : 4,5]pyrimido[1,6-<i>b</i>] [1,2,4]triazines
A number of heterocyclic compounds 5-13 were prepared by the reaction of 6-amino-1,4,5,6-tetrahydro-5-imino-3-methyl-1,4-diphenylpyrazolo [4′,3′:5,6]pyrano[2,3-d]pyrimidine (3) with ethyl 2-cyano-3-ethoxy-2-propenoate, ethoxymethylenemalononitrile, ethyl cyanoacetate, malononitrile, ethyl pyruvate, oxalyl chloride, ethyl chloroformate, and 3-methyl-4-nitroso-1-phenylpyrazol-5(4H)-one, respectively.