Lithium Hydroxide → HCID 86578773, compound

Participants

Reaction Steps

To a degassed solution of methyl 2-[3-bromo-4-(3,4-dihydro-2H-1-benzopyran-6-yl)-1-methyl-1H-pyrazol-5-yl]-2-(tert-butoxy)acetate (11i) (50 mg, 0.114 mmol) in dioxane (1 mL) was added Palladium (II) acetate (1.3 mg, 0.006 mmol) and 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (4.7 mg, 0.011 mmol). After stirring for 30 minutes at room temperature, potassium carbonate (47 mg, 0.343 mmol) in solution in water (0.25 mL) and 4,4,5,5-tetramethyl-2-(5-propylthiophen-3-yl)-1,3,2-dioxaborolane (11c) (40 mg, 0.160 mmol) were added and the reaction mixture was heated at 110° C. until consumption of the starting materials. Then lithium hydroxide (11 mg, 0.46 mmol) was added. The heating was maintained until completion of the reaction. The mixture was concentrated in vacuo. Water (2 mL) was added to the residue and the aqueous layer was washed with diethyl ether (2 mL), acidified with 1M hydrochloric acid until pH 3 and extracted with ethyl acetate (2×3 mL). The organic layer was dried over sodium sulfate and concentrated in vacuo to provide 2-(tert-butoxy)-2-[4-(3,4-dihyd ro-2H-1-benzopyran-6-yl)-1-methyl-3-(5-propylthiophen-3-yl)-1H-pyrazol-5-yl]acetic acid (example 11) (40 mg, 0.09 mmol, 75%).

Provenance & Evidence