These common heterocyclic compound, 13745-17-0, name is 4-Bromo-1H-pyrazole-3-carboxylic acid, 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. name: 4-Bromo-1H-pyrazole-3-carboxylic acid
NaH (60% dispersion in mineral oil, 11.3 g, 282 mmol, 3.0 eq) was added in portions to a mixture of 4-bromo-1H-pyrazole-3-carboxylic acid (18 g, 94.2 mmol, 1.0 eq) in) anhydrous DMF (200 mL) at 0 C under argon protection. Once addition of NaH was complete, the mixture was stirred for an additional 30 min at 0C and 1h at RT. The mixture was re-cooled to 0C and then MeI (24 mL, 377 mmol, 4.0 eq) was added. The reaction mixture was diluted with EtOAc and washed with Sat’d NaHCO3, brine and dried over Na2SO4. The organic layers were concentrated to provide the crude as solid that was used without further purification. 1H NMR (400 MHz, CDCl3) delta 7.87 (s, 1H), 3.96 (s, 3H), 3.88 (s, 3H).
The synthetic route of 4-Bromo-1H-pyrazole-3-carboxylic acid has been constantly updated, and we look forward to future research findings.