1260243-04-6

制备方法

94-05-3

1260243-04-6
以乙氧甲叉氰乙酸乙酯为原料合成5-氨基-1H-吡唑-4-羧酸乙酯的一般步骤如下:将乙氧甲叉氰乙酸乙酯(68g,0.4mol)加入装有200mL无水乙醇的反应容器中;缓慢滴加100mL水合肼至反应容器中,随后将反应体系置于电热套中,于30分钟内逐步升温至80℃,得到混合物A;将混合物A加热至回流状态,保持回流反应4小时。反应完成后,通过减压蒸馏除去乙醇,剩余固体经蒸发处理。将所得固体冷却至室温,静置析出浅黄色固体,经过滤、洗涤及干燥,得到中间体5-氨基-1H-吡唑-4-羧酸乙酯。洗涤过程中使用冷的无水乙醇。最终获得5-氨基-1H-吡唑-4-羧酸乙酯41.68g,收率为66.78%。
参考文献:
[1] Patent: CN105949202, 2016, A. Location in patent: Paragraph 0048-0053
[2] Patent: CN106008517, 2016, A. Location in patent: Paragraph 0048; 0049; 0050; 0051; 0052; 0053
[3] Patent: CN106008519, 2016, A. Location in patent: Paragraph 0048; 0049; 0050; 0051; 0052; 0053
[4] Patent: CN105949199, 2016, A. Location in patent: Paragraph 0047-0052
[5] Patent: CN105949200, 2016, A. Location in patent: Page/Page column 6; 7; 23