A facile synthesis of certain 4- and 4,5-disubstituted 1-β-d-ribofuranosylpyrazoles
作者:Birendra K. Bhattacharya、Roland K. Robins、Ganapathi R. Revankar
DOI:10.1002/jhet.5570270358
日期:1990.3
A number of pyrazole ribonucleosides, structurally related to AICA riboside and ribavirin have been prepared and evaluated for their biological activity in vitro. Deisopropylidenation of 5-amino-1-(2,3-O-isopropylidene-β-D-ribofuranosyl)pyrazole-4-carbonitrile (6) with aqueous trifluoroacetic acid gave 5-amino-1-(β-D-ribofuranosyl)pyrazole-4-carbonitrile (7). Conventional transformation of the carbonitrile
已经制备了结构上与AICA核糖苷和利巴韦林有关的许多吡唑核糖核苷,并对其体外生物活性进行了评估。用三氟乙酸水溶液对5-氨基-1-(2,3 - O-异亚丙基-β-D-呋喃呋喃糖基)吡唑-4-腈(6)进行异异丙基化,得到5-氨基-1-(β-D-呋喃呋喃糖基)吡唑-4-腈(7)。对7的腈的常规转化产生了AICA核糖苷同源物(2)和相关的5-氨基-1-(β-D-核呋喃糖基)-吡唑(8-10)。在低温下乙酰化7得到通用的中间体5-amino-1-(2,3,5-tri- O-乙酰基-β-D-呋喃核糖基)吡唑-4-腈(15)。用异戊基亚硝酸盐在二溴甲烷或二碘甲烷中进行非水重氮化15,得到相应的C 5-溴13和C 5-碘16衍生物。随后将化合物13和16转化成5-溴-1-(β-D-呋喃核糖基)吡唑-4-羧酰胺(11)和5-碘类似物25。但是,类似的15在二氯甲烷中的非水重氮化可得到脱氨基的产物1-(2,3