These common heterocyclic compound, 35691-93-1, name is Ethyl 3,5-dimethyl-1H-pyrazole-4-carboxylate, 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. 35691-93-1
EXAMPLE 20; 2-((S)-1-(3-Fluoro-phenyl)-3-{5-[3,5-dimethyl-1-(6-trifluoromethyl-pyridazin-3-yl)-1H-pyrazole-4-carbonyl]-hexahydro-pyrrolo[3,4-c]pyrrol-2-yl}-propylcarbamoyl)-cyclopentanecarboxylic acid (II-1); Step 1-; To a solution of 3,5-dimethyl-1H-pyrazole-4-carboxylic acid ethyl ester (0.2 g, 1.19 mmol) in DMF (10 mL) cooled to 0 C. was added sequentially NaH (60% in mineral oil, 72 mg, 1.78 mmol) and 3-chloro-6-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 NH4CI. 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 SiO2 chromatography eluting with hexane/EtOAc to afford 0.228 g (62%) of 92a.
Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 35691-93-1.