Dichloromethane → Ethyl 6-(1-methyl-1H-pyrazol-5-yl)pyrazolo[1,5-a]pyridine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture comprising ethyl 6-bromopyrazolo[1,5-a]pyridine-3-carboxylate (1.5 g, 5.57 mmol), 1-methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1.218 g, 5.85 mmol), cesium carbonate (7.26 g, 22.30 mmol) and PdCl2(dppf).CH2Cl2 adduct (91 mg, 0.111 mmol) in DME (10 ml) and water (4.00 ml) was heated using microwave radiation at 70° C. for 1 hr. Further PdCl2(dppf).CH2Cl2 adduct (91 mg, 0.111 mmol) was added and the mixture was heated at 80° C. for 1 hr. 1-Methyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1.218 g, 5.85 mmol) and PdCl2(dppf).CH2Cl2 adduct (91 mg, 0.111 mmol) were added and heating continued at 100° C. for 3 hrs. The mixture was diluted with 10% MeOH in EtOAc (200 ml) and washed with sat. NaHCO3. The organic solvent was removed under vacuum and azeotroped with toluene. The resulting solid was loaded onto silica and purified by chromatography eluting with 0-100% EtOAc in iso-hexane to afford the title compound;

Provenance & Evidence