A facile synthetic route to substituted 6,8-dimethyl-3,3a,4, 5-dihydro-2H-pyrazolo[3′,4′:4,5]pyrido[2,3-d]pyrimidine-] 7,9(6H,8H)-di-ones is described based on an intramolecular azomethine imine cyclization followed by dehydrogenation. The azomethine imine intermediates are given by the thermal 1,2-hydrogen shift of the hydrazones, which are formed from the reaction of 6-allylamino-5-formyl-1, 3-dimethyl-2,4(1H,3H)-pyrimidinediones and hydrazines 2.
基于分子内氮
亚胺环化和脱氢反应,描述了取代的 6,8-二甲基-3,3a,4,5-二氢-2H-
吡唑并[3′,4′:4,5]
吡啶并[2,3-d]
嘧啶-]7,9(6H,8H)-二酮的简便合成路线。偶氮
亚胺中间体是由 6-烯丙基
氨基-5-甲酰基-1,3-二甲基-2,4(1H,3H)-
嘧啶二酮和
肼 2 反应生成的
肼的 1,2-氢热移给出的。