1260169-02-5

基本信息
2-Aminopyrazolo[1,5-a]pyrimidine-3-carboxylic acid ethyl ester
Pyrazolo[1,5-a]pyrimidine-3-carboxylic acid, 2-amino-, ethyl ester
物理化學性質(zhì)
制備方法

102-52-3

6825-71-4
![2-氨基吡唑并[1,5-A]嘧啶-3-羧酸乙酯](/CAS/20180808/GIF/1260169-02-5.gif)
1260169-02-5
以3,5-二氨基-1H-吡唑-4-羧酸乙酯(5.00g,29.38mmol)和1,1,3,3-四甲氧基丙烷(14.50mL,88.15mmol)為原料,在DMF(80mL)中反應。加入AcOH(0.34mL,5.88mmol)作為催化劑。將反應混合物在100℃下攪拌14小時。反應完成后,通過真空濃縮去除溶劑。將殘余物在DCM(50mL)和水(50mL)之間分配,分離有機相。水相用DCM(100mL×3)萃取。合并有機相,用鹽水(100mL)洗滌,經(jīng)無水Na2SO4干燥,過濾并真空濃縮。通過硅膠柱色譜法(洗脫劑:NH3在MeOH中的溶液(7M)/DCM(v/v)=1/100)純化殘余物,得到2-氨基吡唑并[1,5-a]嘧啶-3-羧酸乙酯,為淺黃色固體(3.52g,收率58.1%)。MS(ESI,陽離子)m/z:207.1 [M+H]+;1H NMR(400MHz,CDCl3):δ(ppm)8.60(dd,J=4.40Hz,1.76Hz,1H),8.46(dd,J=6.76Hz,1.76Hz,1H),6.86(dd,J=6.72Hz,4.40Hz,1H),4.50(q,J=7.08Hz,2H),1.47(t,J=7.08Hz,3H)。
參考文獻:
[1] Patent: WO2015/73267, 2015, A1. Location in patent: Paragraph 318
[2] Patent: CN104650092, 2017, B. Location in patent: Paragraph 0463-0464; 0473-0474
[3] Patent: WO2011/3065, 2011, A2. Location in patent: Page/Page column 110-111
[4] Patent: US2015/336962, 2015, A1. Location in patent: Paragraph 0478
[5] Patent: WO2017/48702, 2017, A1. Location in patent: Paragraph 001169; 001170; 001172