Tetrahydrofuran → HCID 22870807, compound

Participants

Reaction Steps

To a solution containing (3S-trans)-α-amino-N-(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-yl)benzeneacetamide (340 mg, 0.97 mmol; isomer A of the title compound of Example 2) in tetrahydrofuran (10 mL, a few drops of methanol were added to obtain a clear solution) at room temperature was slowly added excess acetyl chloride while maintaining the reaction at pH ~8.5 by simultaneous addition of 7% sodium carbonate solution. After the completion of the reaction, it was diluted with ethyl acetate and washed with water and brine. After drying over anhydrous magnesium sulfate, the solvent was evaporated to provide a colorless solid (320 mg, 84.2%) which was recrystallized from hot 2-propanol to give (3S-trans)-N-[2-[(6-cyano-3,4-dihydro-3-hydroxy-2,2-dimethyl-2H-1-benzopyran-4-yl )amino]-2-oxo-1-phenylethyl]acetamide, mp 234°-236° C. Analysis calculated for C22H23N3O4.0.2H2O: C, 66.55; H, 5.94; N, 10.58. Found: C, 66.71; H, 5.58; N, 10.56. [α]D =-91.2° (c =0.5, MeOH).

Provenance & Evidence