Acetic Acid → (R)-3-(N-cyclopentylamino)-8-fluoro-5-methoxy-3,4-dihydro-2H-1-benzopyran

Participants

Reaction Steps

To a solution of (R)-3-amino-8-fluoro-5-methoxy-3,4-dihydro-2H-1-benzopyran (0.7 g, 3.4 mmol), cyclopentanone (0.7 g, 8.3 mmol) and HOAc (0.2 g, 3.5 mmol) in methanol (25 mL), NaCNBH3 (0.7 g, 10 mmol) was added in portions at room temperature. The solution was stirred at room temperature over night. The methanol was evaporated. The residue was dissolved in EtOAc and washed with water. The organic layer was dried with Na2SO4 and the solvent was evaporated to give 0.9 g (100% yield) of the title compound as a colourless oil. GC indicated 99.6 purity. GC/MS (70 eV) M=265 (30%).

Provenance & Evidence