Reference of 399-94-0, 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. 399-94-0, name is 1-Bromo-2,5-difluorobenzene belongs to bromides-buliding-blocks compound, it is a common compound, a new synthetic route is introduced below.
Preparation A; (R)-2-(2,5-difluorophenyl)pyrrolidine; Step A: Preparation of (RVtert-butyl 2-(2.5-difluorophenyl)pyrrolidine-l- carboxylate.; A solution of tert-butyl pyrrolidine- 1-carboxylate (20 g, 116.8 mmol) and (-)- sparteine (32.9, 140 mmol) in MTBE (360 mL) was cooled to -78 0C and sec-BuU (100 mL, 140 mmol, 1.4 M in cyclohexane) was introduced drop-wise via cannula, keeping the internal temperature under -70 0C. The resulting solution was stirred for 3 hours at -78 0C, followed by addition of a solution of ZnCl2 (93.4 mL, 93.4 mmol, IM in Et2O) drop-wise with rapid stirring, keeping the internal temperature below -65 0C. The resulting light suspension was stirred at -78 0C for 30 minutes and then warmed to ambient temperature. The resulting mixture was sequentially charged with 2-bromo-l,4-difluorobenzene (14.5 mL, 128 mmol), Pd(OAc)2 (1.31 g, 5.8 mmol) and J-Bu3P-HBF4 (2.03 g, 7.0 mmol) in one portion. After stirring overnight at ambient temperature, concentrated NH4OH (10.5 mL) was added and the reaction was stirred for 1 hour. The resulting slurry was filtered through Celite and the filter cake washed with Et2O (1 L). The filtrate was washed with a IM aqueous HCl solution (0.5 L) and brine. The organic layer was filtered and concentrated, and the crude product was purified by silica column chromatography, eluting with 5-10% EtOAc/hexanes to give product (R)-tert-butyl 2-(2, 5 -difluorophenyl)pyrrolidine- 1-carboxylate as yellow oil (23.9 g, 72% yield).
In the field of chemistry, the synthetic routes of compounds are constantly being developed and updated. I will also mention this compound in other articles, 1-Bromo-2,5-difluorobenzene, other downstream synthetic routes, hurry up and to see.
Reference:
Patent; ARRAY BIOPHARMA INC.; ALLEN, Shelley; ANDREWS, Steven S.; CONDROSKI, Kevin Ronald; HAAS, Julia; HUANG, Lily; JIANG, Yutong; KERCHER, Timothy; SEO, Jeongbeob; WO2011/6074; (2011); A1;,
Bromide – Wikipedia,
bromide – Wiktionary