Dihydrocoumarin → 2,3-Dihydro-1-benzofuran-7-carboxylic acid

Temperature

20 °C

A solution of dihydrocoumarin (0.338 mL, 3.00 mmol) in dry diethyl ether (10 mL) was cooled to -78° C. and a solution of n-butyllithium in hexane (2.38M, 1.30 mL, 3.00 mmol) was slowly added. The reaction was stirred at 20° C. overnight. The reaction was cooled to -78° C. and carbon dioxide was bubbled through for 10 min. The reaction was warmed to 20° C. and partitioned between water and ether. A solution of 10% aqueous HCl was added to the aqueous phase until the pH was less than 1. The aqueous phase was washed with ether, and the ether washed with saturated sodium chloride solution. The title compound was obtained as a white solid (0.175 g). NMR (CDCl3, 300 MHz) δ 7.83 (1H, d, J=8 Hz), 7.42 (1H, d, J=8 Hz), 6.96 (1H, t, J=8 Hz), 4.80 (2H, t, J=8 Hz), 3.30 (2H, t, J=8 Hz).

1. temperatureThe reaction was cooled to -78° C.
2. customcarbon dioxide was bubbled through for 10 min
3. temperatureThe reaction was warmed to 20° C.
4. custompartitioned between water and ether
5. additionA solution of 10% aqueous HCl was added to the aqueous phase until the pH was less than 1
6. washThe aqueous phase was washed with ether
7. washthe ether washed with saturated sodium chloride solution

ORD record

ord-860ea639e22245c28e771f14c907f17b

Source dataset

uspto-grants-1998_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05736539