Reference of 35691-93-1,Some common heterocyclic compound, 35691-93-1, name is Ethyl 3,5-dimethyl-1H-pyrazole-4-carboxylate, molecular formula is C8H12N2O2, 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.
step 1 – To a solution of 3,5-dimethyl-lff-pyrazole-4-carboxylic acid ethyl ester (0.2 g, 1.19 mmol) in DMF (10 mL) cooled to O0C was added sequentially NaH (60% in mineral oil, 72 mg, 1.78 mmol) and S-chloro-?-trifluoromethyl-pyridazine (0.22 g, 1.21 mmol; Tetrahedron 1999 55:15067-15070). The resulting mixture was stirred at RT for 3 h then partitioned between EtOAc and saturated aqueous NH4Cl. The layers were separated and the aqueous layer was extracted twice with EtOAc. The combined extracts were dried (Na2SO4), filtered and evaporated. The residue was purified via Si?2 chromatography eluting with hexane/EtOAc to afford 0.228 g (62%) of 118a.
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Ethyl 3,5-dimethyl-1H-pyrazole-4-carboxylate, its application will become more common.