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. 19968-17-3, name is 4-Bromo-3-(trifluoromethyl)-1H-pyrazole, A new synthetic method of this compound is introduced below., HPLC of Formula: C4H2BrF3N2
4-Bromo-1-{[(4R)-2,2-dimethyl-1,3-dioxolan-4-yl]methyl}-5-(trifluoromethyl)-1H-pyrazole and 4-bromo-1-{[(4R)-2,2-dimethyl-1,3-dioxolan-4-yl]methyl}-3-(trifluoromethyl)-1H-pyrazole; A mixture of 4-bromo-3-trifluoromethyl-1H-pyrazole (400.0 mg, 1.861 mmol), toluene-4-sulfonic acid (S)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl ester (799.2 mg, 2.791 mmol), K2CO3 (400.0 mg, 2.894 mmol) and DMF (6 mL, 80 mmol) was heated to 90 C. for 2 h. The material was extracted with EtOAc, washing with water (3¡Á). The organic layer was dry-loaded onto silica gel, and purified via column chromatography, eluting with 10-30% EtOAc/heptane. The fractions containing each pure product were concentrated in vacuo to afford the title compounds as clear oils. 3-Trifluoromethyl isomer: 1H NMR (400 MHz, CD3OD): delta=1.31 (s, 3H), 1.34 (s, 3H), 3.78 (dd, J=8.6, 5.8 Hz, 1H), 4.10 (dd, J=8.8, 6.6 Hz, 1H), 4.22-4.31 (m, 1H), 4.36 (dd, J=14.1, 4.0 Hz, 1H), 4.41-4.49 (m, 1H), 7.92 (s, 1H). MS (ES+): m/z=329.01/331.01 (100/100) [MH+]. HPLC: tR=1.59 min (polar-3 min, UPLC-ACQUITY). 5-Trifluoromethyl isomer: MS (ES+): m/z=329.01/331.01 (100/100) [MH+]. HPLC: tR=1.62 min (polar-3 min, UPLC-ACQUITY).
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.