Some common heterocyclic compound, 73387-52-7, name is 5-(4-Bromophenyl)-1-methyl-1H-pyrazole, molecular formula is C10H9BrN2, 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. name: 5-(4-Bromophenyl)-1-methyl-1H-pyrazole
Inside an argon filled glove bag, 3.41 g of sodium f-butoxide was placed in an oven-dried flask. 7.03 g of 5-(4-bromophenyl)-1 -methyl-1 /-/-pyrazole, 0.328 g of palladium acetate, and 0.7720 g of 1 ,1 ‘-bis(di-i-propylphosphino)-ferrocene were added, and the mixture was evacuated/nitrogen filled three times. 50 ml_ of anhydrous 1 ,4-dioxane was added, followed by the addition of 7.00 ml_ of triisopropylsilanethiol. After heating at reflux for 40 minutes, the reaction mixture was cooled, and 20 ml_ of 2.5 N aqueous sodium hydroxide and 15 ml_ of DMSO were then added under nitrogen. The reaction was stirred vigorously at room temperature for 40 minutes and then diluted into ether. The addition of 125 ml_ of 5% aqueous sodium chloride containing ~5 ml_ of concentrated hydrochloric acid adjusted the pH of the aqueous phase to 4, and the mixture was extracted, separated, extracted the aqueous again with ether, combined the ether extracts, dried with magnesium sulfate, filtered, and concentrated to give a dark liquid. The crude product was diluted into ether, extracted twice with 100-mL portions of 0.5 N aqueous sodium hydroxide (discarded the ether), combined the aqueous extracts, extracted the aqueous solution with ether (discarded ether), carefully adjusted the pH to 3 with concentrated hydrochloric acid, extracted three times with ether, combined the ether extracts, dried with magnesium sulfate, filtered, concentrated, and flash chromatographed on silica gel to give 4.4600 gm of product. 1 H NMR (400 MHz, DMSO-c/e) delta ppm 3.83 (s, 3 H) 5.65 (s, 1 H) 6.36 (d, J=1.95 Hz, 1 H) 7.40 (s, 4 H) 7.44 (d, J=1.95 Hz, 1 H).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 73387-52-7, its application will become more common.
Reference:
Patent; PFIZER INC.; WO2009/69044; (2009); A1;,
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics