Application of 67-51-6, These common heterocyclic compound, 67-51-6, name is 3,5-Dimethyl-1H-pyrazole, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
Powdered potassium hydroxide (1.751 g, 31.2 mmol) was added to a solution of 3,5-dimethylpyrazole (2 g, 20.81 mmol) in anhydrous DMSO (10.40 ml) and the resulting heterogeneous solution was stirred for 1.5 hr at 80 C before being cooled to roomtemperature. 2-Chloro benzylchloride (2.64 ml, 20.81 mmol) was then added in 6 M DMSO over 15 min, and the solution was stirred for a further 1.5 hrs. Upon completion as observed by TLC, the reaction was poured over water and the resulting aqueous phase was extracted with two 20 mL portions of CHCI3. The combined organic layers were washed with 100 mL of water, dried with anhydrous MgS04 and concentrated under reduced pressure to yield 4.55 g (99%) of l-(2-chlorobenzyl)-3,5-dimethyl-lH-pyrazole as a clear liquid. 1H NMR (300 MHz, CDCI3) delta 7.41 – 7.31 (m, 1H), 7.24 – 7.09 (m, 2H), 6.59 – 6.50 (m, 1H), 5.90 (s, 1H), 5.31 (s, 2H), 2.26 (s, 3H), 2.15 (s, 3H). 13C NMR (75 MHz, CDCI3) delta 148.32, 139.96, 135.46, 131.96, 129.42, 128.76, 127.72, 127.48, 105.84, 50.12, 13.80, 11.15. HRMS (m z): [MNa]+ calc for C12Hi3ClN2Na+ 243.07; found 243.0651.
Statistics shows that 3,5-Dimethyl-1H-pyrazole is playing an increasingly important role. we look forward to future research findings about 67-51-6.