Phosphoric Acid → HCID 90022049, compound

Participants

Reaction Conditions

Reaction Steps

Into a 100-mL three neck round-bottom flask, which was purged and maintained with an inert atmosphere of argon, was placed a solution of 2,2,2-trifluoroethyl 4-methylbenzenesulfonate (1.00 g, 3.93 mmol) in THF (30 mL). The solution was cooled to −78° C., then n-BuLi (5.0 mL, 1.6 M in hexane, 8.0 mmol) was added drop-wise and the mixture was stirred at −78° C. for 40 min Triethylborane (TEB) (5.0 mL, 1 M in THF, 5.0 mmol) was slowly added and the mixture was stirred at −78° C. for 1 h, then at room temperature for 3 h. The solution was cooled to 0° C., then hexamethylphosphoramide (HMPA) (6 mL) and CuI (1.5 g, 7.9 mmol) were added and the mixture was stirred at room temperature for 30 min. A solution of methyl 5-(chlorocarbonyl)-2,4-dimethylbenzoate (compound 255.2, 530 mg, 2.34 mmol) in THF (30 mL) was carefully added and stirred at room temperature for 30 min. The pH of the mixture was carefully adjusted to 7 with aqueous H3PO4 and the mixture was partitioned. The aqueous phase was extracted with ethyl acetate (3×20 mL) and the combined organic layers were concentrated under reduced pressure. The residue was purified by silica gel column chromatography with ethyl acetate/petroleum ether (1:40) as eluent to obtain the title compound as a yellow oil (250 mg, 38%).

Provenance & Evidence