5409-39-2
21427-62-3
(步驟1)將5-氯-3-硝基吡啶-2-胺(10.0g,57.6mmol)溶解于濃鹽酸(100mL)中,冷卻至-10℃并持續(xù)攪拌。在30分鐘內(nèi),緩慢滴加亞硝酸鈉(9.94g,144mmol)的水溶液(20mL)。滴加完畢后,保持反應(yīng)混合物在0℃下繼續(xù)攪拌1小時(shí)。隨后,用1N氫氧化鈉水溶液調(diào)節(jié)反應(yīng)液的pH至9,然后用乙酸乙酯進(jìn)行萃取。過濾去除不溶性雜質(zhì),有機(jī)層用飽和鹽水洗滌,并用無水硫酸鎂干燥。過濾后,通過減壓蒸餾除去溶劑,得到目標(biāo)產(chǎn)物2,5-二氯-3-硝基吡啶(6.50g,收率:58.5%),為固體。1H-NMR(CDCl3)δ:8.60(1H,d,J = 2.9Hz),8.24(1H,d,J = 2.6Hz)。
參考文獻(xiàn):
[1] Patent: WO2007/67875, 2007, A2. Location in patent: Page/Page column 15
[2] Patent: JP2016/56134, 2016, A. Location in patent: Paragraph 0165; 0166; 0167
[3] Patent: JP2016/56133, 2016, A. Location in patent: Paragraph 0158; 0159
[4] Patent: EP3109239, 2016, A1. Location in patent: Paragraph 0189
[5] Journal of the Chemical Society, 1952, p. 2042,2044