Synthesis of 4,6-disubstituted-7-β-D-ribofuranosyl- and arabinofuranosylpyrazolo[3,4-d]pyrimidines and certain related ribonucleosides
作者:T. Sudhakar Rao、Ganapathi R. Revankar、Ravi S. Vinayak、Roland K. Robins
DOI:10.1002/jhet.5570280722
日期:——
C4-pyridinium chloride intermediate 17. Condensation of the TMS derivatives of 7-hydroxy- (20) or 7-aminopyrazolo[1,5-a]pyrimidin-5(4H)-one (23) with 5 in the presence of TMS triflate gave the corresponding blocked nucleosides 21 and 24, respectively, which on deprotection afforded 7-hydroxy- 22 and 7-amino-4-β-D-ribofuranosylpyrazolo[1,5-a]pyrimidin-5-one (25), respectively. Similarly, starting either
已经制备了几种双取代的吡唑并[3,4- d ]嘧啶,吡唑并[1,5- a ]嘧啶和噻唑并[4,5- d ]嘧啶核糖核苷,作为尿苷和胞苷的同源物。吡唑并[3,4- d ]嘧啶-4,6(1 H,5 H,7 H)-二酮(4)的三甲基甲硅烷基(TMS)衍生物与1- O-乙酰基-2,3,5-的糖基化在三氟甲磺酸酯存在下,三邻苯甲酰基-D-呋喃核糖(5)得到7-(2,3,5-三邻苯甲酰基-β-D-呋喃呋喃糖基)吡唑并-[3,4- d ]嘧啶-4,6-(1 ħ,5 ħ-二酮(6)。6的脱苯甲酰化得到尿苷类似物7-β-D-呋喃核糖基吡唑并[3,4- d ]嘧啶-4,6(1 H,5 H)-二酮(3),与先前报道的7-核呋喃基糖基氧代嘌呤醇相同。6的硫杂化合物得到7,在脱苯甲酰化后得到7-β-D-呋喃呋喃糖基-6-氧杂唑并[3,4- d ]嘧啶-4(1 H,5 H)-硫酮(8)。在高温下对7进行氨解会降低胞苷