1202993-11-0

基本信息
5-氯-3-(二氟甲基)-1-甲基-1H-吡唑-4-羧酸
5-Chloro-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxyli...
5-Chloro-3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic Acid
1H-Pyrazole-4-carboxylic acid, 5-chloro-3-(difluoroMethyl)-1-Methyl-
物理化學性質
制備方法

660845-30-7

1202993-11-0
在500 mL三口燒瓶中,將6.0 g(31 mmol)5-氯-3-(二氟甲基)-1-甲基-1H-吡唑-4-甲醛溶解于30 mL甲苯中。向該溶液中緩慢加入2.4 g(62 mmol)氫氧化鈉溶于6 mL水的溶液,隨后在溫度控制在37℃以下的條件下,滴加103 mL 30%過氧化氫水溶液。反應混合物在50℃下攪拌反應7小時。反應完成后,冷卻至室溫,分離有機相和水相。用100 mL水萃取有機相,合并水相。用稀鹽酸水溶液將合并的水相酸化至pH 2,析出白色沉淀。過濾收集沉淀,用20 mL水洗滌兩次,干燥后得到3.2 g 5-氯-3-(二氟甲基)-1-甲基-1H-吡唑-4-羧酸,為白色固體。產(chǎn)物經(jīng)1H NMR(400 MHz,DMSO-d6)表征:δ 3.78(s,3H),7.12(t,1H,JHF = 53.60 Hz),13.19(s,1H);IR(KBr)顯示:1688 cm-1(C=O伸縮振動),2200-3200 cm-1寬峰(氫鍵振動)。
參考文獻:
[1] Patent: EP2251331, 2010, A1. Location in patent: Page/Page column 24
[2] Patent: WO2011/151369, 2011, A1. Location in patent: Page/Page column 63
[3] Patent: WO2011/151370, 2011, A1. Location in patent: Page/Page column 90
[4] Patent: WO2012/52491, 2012, A2. Location in patent: Page/Page column 43
[5] Patent: WO2012/52490, 2012, A1. Location in patent: Page/Page column 68