C-nucleoside studies. Part 14. A new synthesis of pyrazofurin
作者:J. Grant Buchanan、Alan Stobie、Richard H. Wightman
DOI:10.1039/p19810002374
日期:——
Treatment of 3-cyano-4-nitro-5-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)pyrazole (4) with benzyl bromide and triethylamine gave as major product the 1-benzyl-5-cyano-isomer (5), whilst similar treatment of 5-cyano-3-methyl-4-nitropyrazole (7) gave exclusively 1-benzyl-3-cyano-5-methyl-4-nitropyrazole (8). This was converted into 4-amino-1-benzyl-3-carboxamido-5-methylpyrazole (10); attempts to convert
用苄基溴和三乙胺处理3-氰基-4-硝基-5-(2,3,5-三-O-乙酰基-β - D-呋喃呋喃糖基)吡唑(4),得到的主要产物是1-苄基-5 -氰基异构体(5),同时对5-氰基-3-甲基-4-硝基吡唑(7)进行类似处理,仅得到1-苄基-3-氰基-5-甲基-4-硝基吡唑(8)。将其转化为4-氨基-1-苄基-3-甲酰胺基-5-甲基吡唑(10); m / z(MH +)。尝试通过重氮盐将(10)转化为4-羟基吡唑没有成功,但是重氮盐(11)在三氟乙酸-二恶烷水溶液中的光解得到67中的1-苄基-3-甲酰胺基-5-甲基吡唑(13) % 屈服。