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。