Reference of 1996-30-1, In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 1996-30-1, name is 3-Bromo-4-fluorochlorobenzene belongs to chlorides-buliding-blocks compound, it is a common compound, a new synthetic route is introduced below.
[00227] Step 12. 3-Bromo-5-chloro-2-fluorobenzaldehyde. A solution of 2,2,6,6- tetramethylpiperidine (327 g, 98%, 2.274 mol) and THF (1.9 L, HPLC grade) was cooled to -75 0C (dry ice-methanol bath) under an argon atmosphere. 1.6 M n-BuLi/hexane solution (1.47 L, 2.35 mol) was added slowly into the mixture at -72 to -67 0C over 1 h. The mixture was stirred at -72 to -67 0C for 30 min to give a pale yellow suspension. 2-Bromo-4-chloro-l-fluorobenzene (435 g, 97%, 2.02 mol) was added slowly into the mixture at -72 to -67 0C over 30 min, and then the mixture was stirred at -72 to -67 0C for an additional 30 min. Dimethylformamide (230 g, 99.5%, 3.14 mol) was added slowly into the mixture at -70 to -65 0C over 30 min and then the mixture was stirred at -70 to -65 0C for 30 min to afford a light brown solution. The cooling bath was removed and then saturated ammonium chloride solution (720 mL) was added into the batch at -60 to -30 0C over 15 min to obtain a hazy mixture. 6 N hydrochloric acid was quickly added into the mixture at -30 to 10 0C over 15 min to pH 1 and then ethyl acetate (2.0 L) was added at 10 to 20 0C. The layers were separated and the aqueous layer was extracted with ethyl acetate (1 x 300 mL). The combined organic extracts were washed with water (I x 800 mL) and brine (I x 500 mL), dried over magnesium sulfate, and filtered. The filtrate was concentrated under vacuum (60-65 0C) to give the title compound as a tan viscous oil, which solidified upon standing after several hours. 1H NMR (CDCl3): delta 7.76-8.30 (m, 2H), 10.0-10.8 (br s, IH); MS m/z 238.0 (M+l).
The synthetic route of 3-Bromo-4-fluorochlorobenzene has been constantly updated, and we look forward to future research findings.
Reference:
Patent; IRM LLC; NOVARTIS AG; HUANG, Shenlin; JIN, Xianming; LIU, Zuosheng; POON, Daniel; TELLEW, John; WAN, Yongqin; WANG, Xing; XIE, Yongping; WO2011/25927; (2011); A1;,
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