1-甲基-3-正丙基-4-硝基吡唑-5-甲酰胺的合成工艺改进

Improved Synthetic Process of 1-Methyl-4-nitro-3-n- propylpyrazole-5-carboxamide

1-甲基 - 3-正丙基 - 4-硝基吡唑 - 5 -甲酰胺是合成磷酸二酯酶 V型 (PDE5 )抑制剂 Sildenafil Citrate的重要中间体 ,在文献基础上合成了标题化合物。经改进 ,将六步反应合并为四步进行 ,并相应改变反应条件。反应周期缩短 ,总收率自 15 %提高至 41% 。

Methyl 4 nitro 3 n propylpyrazole 5 carboxamide, the key intermediate in the synthesis of sildenafil citrate (Viagra), was prepared in six steps with about 15% total yield as described in the literatures. An improved process for preparing has been developed in four steps with the overall yield of 41%.