Sodium Bicarbonate → HCID 68513538, compound

Participants

Reaction Steps

A solution of the compound of example (45)(20 g, 37.5 mmol) in dioxane (150 mL) was added dropwise to a suspension of sodium hydride (60% dispersion, 5.68 g, 142 mmol) in dioxane (50 mL) and the reaction mixture stirred at room temperature for 12 hrs. The reaction mixture was quenched with dropwise addition of methanol and the solvents evaporated under reduced pressure. The residue was acidified with dilute HCl, basified with 10% NaHCO3 solution to pH 8 to 9 and extracted with EtOAc (3×250 mL). The organic layer was washed with water (50 mL), brine (50 mL), dried over anhydrous Na2SO4 and concentrated under reduced pressure to give acetic acid 3-{3-[3-(2-chloro-4-nitrophenyl)-3-oxopropionyl]-2-hydroxy-4,6-dimethoxyphenyl}-1-methyl-pyrrolidin-2-ylmethyl ester as an oil (18.2 g). This ester was dissolved in conc. HCl (50 mL) and stirred at room temperature for 3 hrs. At the end of 3 hrs, the reaction mixture was basified with solid NaHCO3 to pH 8 to 9. The aqueous layer was extracted with chloroform (3×250 mL) and washed with water (50 mL) and brine (50 mL). The organic layer was dried over anhydrous Na2SO4, concentrated under reduced pressure and dried over vacuum. The residue was purified by column chromatography with 3% methanol in chloroform and 0.1% ammonia as eluent to yield the compound (+)-trans-2-(2-chloro-4-nitrophenyl)-8-(2-hydroxymethyl-1-methylpyrrolidin-3-yl)-5,7-dimethoxy-chromen-4-one as a pale yellow solid.

Provenance & Evidence