Hydrochloric Acid → (+)-trans-2-(2-Chloro-phenyl)-8-(2-hydroxymethyl-1-methyl-pyrrolidin-3-yl)-5,7-dimethoxy-chromen-4-one

Beteiligte Stoffe

Reaktionsschritte

Sodium hydride (50%, 2.17 g, 45.3 mmol) was added in portions to a solution of compound of example 6 (2.8 g, 9 mmol) in dry DMF (30 mL) at 0° C., under nitrogen atmosphere and with stirring. After 10 min., methyl 2-chlorobenzoate (5.09 g, 29.9 mmol) was added. The reaction mixture was stirred at 25° C. for 2 h. Methanol was added carefully below 20° C. The reaction mixture was poured over crushed ice (300 g), acidified with 1:1 HCl (pH 2) and extracted using EtOAc (2×100 mL). The aqueous layer was basified using a saturated Na2CO3 (pH 10) and extracted using CHCl3 (3×200 mL). The organic layer was dried (anhydrous Na2SO4) and concentrated. To the residue, conc. HCl (25 mL) was added and stirred at room temperature for 2 h. The reaction mixture was poured over crushed ice (300 g) and made basic using a saturated aqueous Na2CO3 solution. The mixture was extracted using CHCl3 (3×200 mL). The organic extract was washed with water, dried (anhydrous Na2SO4) and concentrated to obtain the title compound.

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