Eine einstufige Synthese von Azolo-anellierten Derivaten des Pyrido[2,3-<i>d</i>]pyrimidins
作者:Oleg N. Chupakhin、Vladimir L. Rusinov、Tatjana, L. Pilicheva、Andrej A. Tumashov
DOI:10.1055/s-1990-26991
日期:——
A One-Pot Synthesis of Azolo-annulated Derivatives of Pyrido[2,3-d]pyrimidine 6-Nitro[1,2,4]triazolo- and 6-nitropyrazolo[1,5-a]pyrimidines 1a-h react with malononitrile and ethyl cyanoacetate to yield 9-imino-, 2a-h, and 9-oxo-7-nitro-4,9-dihydroazolo[1,5-a]pyrido-[2,3-d]pyrimidines 4a-g, respectively. By using the N*C*-double-labelled ethyl cyanoacetate in this reaction, its participation as a 1,3-bifunctional reagent was established. Malononitrile or ethyl cyanoacetate provide the C-C-N fragment for the pyridine ring. The mechanism is discussed.