Electric Literature of 93608-11-8, 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. 93608-11-8, name is 3-Bromo-5-(trifluoromethyl)-1H-pyrazole belongs to pyrazoles-derivatives compound, it is a common compound, a new synthetic route is introduced below.
3-Bromo-l-(4-nitrophenyl)-5-(trifluoromethyl)-l /-pyrazole 23b: To a stirred suspension of 22b (5.0 g, 23.3 mmol, 1.0 equiv) and anhydrous potassium carbonate (3.9 g, 27.9 mmol, 1.2 equiv) in DMF (116 mL), l-fluoro-4-nitrobenzene (2.5 mL, 23.5 mmol, 1.01 equiv) was added at 25 C, and the reaction mixture was heated to 80 C for 12 h. After cooling to 25 C, the reaction mixture was quenched with a saturated aqueous solution of ammonium chloride (20 mL), and the two phases were separated. The aqueous layer was extracted with ethyl acetate (3 chi 15 mL), and the combined organic layers were backwashed with water (2 chi 15 mL) and brine (15 mL), dried with anhydrous magnesium sulfate, and concentrated in vacuo. Flash column chromatography (silica gel, 8% to 20% ethyl acetate in hexanes) with a slow gradient to separate the undesired regioisomer afforded 23b (1.57 g, 4.66 mmol, 20%) as a white amorphous solid. 23b: Ri = 0.61 (silica gel, 20% ethyl acetate in hexanes); FT-IR (neat) V 3149, 2923, 2853, 1598, 1527, 1502, 1454, 1347, 1288, 1216, 1180, 1141, 1112, 1076, 986, 963, 854, 812, 757, 689 cm 1; NMR (600 MHz, CDC13) delta = 8.37 (d, J = 9.0 Hz, 2 H), 7.71 (d, J = 9.0 Hz, 2 H), 6.93 (s, 1 H) ppm; 13C NMR (151 MHz, CDC13) 5 = 148.1, 143.1, 134.3 (q, J = 40.4 Hz), 128.6, 125.9, 124.9, 116.1 (q, J= 270.0 Hz), 113.3 (q, J= 2.6 Hz) ppm; HRMS (ESI) calcd for Ci0H5BrF3N3O2 [M+H]+ 335.9590 found 335.9588.
The synthetic route of 3-Bromo-5-(trifluoromethyl)-1H-pyrazole has been constantly updated, and we look forward to future research findings.
Reference:
Patent; WILLIAM MARSH RICE UNIVERSITY; NICOLAOU, Kyriacos, C.; RHOADES, Derek; WANG, Yanping; TOTOKOTSOPOULOS, Sotirios; (191 pag.)WO2017/66606; (2017); A1;,
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