Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 51776-71-7, name is 1-Bromo-4-(difluoromethyl)benzene, A new synthetic method of this compound is introduced below., Computed Properties of C7H5BrF2
B. Synthesis of 2-[4-(difluoromethyl)phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane[1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(11) (25.25 g, 34.5 mmol) was added in one portion to a degassed mixture of 1-bromo-4-(difluoromethyl)benzene (160 g, 0.77 mol), 4,4,4′,4′,5,5,5′,5′-octamethyl-2,2′-bi-1,3,2-dioxaborolane (392.5 g, 1.55 mol) and potassium acetate (303 g, 3.09 mol) in 1,4-dioxane (2.42 L), and the reaction was heated to 100 C. for 18 hours. The mixture was then cooled to room temperature and filtered through Celite, washing with ethyl acetate (3 L). The filtrate was concentrated in vacuo to give a dark brown oil. The reaction was repeated an additional 3 times, on batches of 50 g, 160 g and 156 g of 1-bromo-4-(difluoromethyl)benzene (total starting material, 526 g, 2.54 mol), and the combined crude products were purified twice by chromatography on silica gel (Gradient: 0% to 3% ethyl acetate in heptane) to provide a yellow-white solid (803 g). This was recrystallized from methanol (1.6 L) at -20 C., and the filtrate was concentrated to one-half its original volume, cooled, and the resulting solid was collected by filtration. The combined solids (426 g) were recrystallized from heptane (500 mL) at -20 C., then melted and poured into methanol (200 mL) cooled in a methanol-ice bath. The mixture was broken up and filtered to yield C5 as a solid. Yield: 250.7 g, 0.987 mmol, 39%. 1H NMR (400 MHz, CDCl3) delta 1.37 (s, 12H), 6.65 (t, J=56.4 Hz, 1H), 7.52 (br d, J=8.1 Hz, 2H), 7.92 (br d, J=8.0 Hz, 2H).
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.
Reference:
Patent; Pfizer Inc.; US2012/214791; (2012); A1;,
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bromide – Wiktionary