Ethanol → 2,3-Dihydro-1,4-benzodioxin-5-acetic acid

Participants

Reaction Steps

To a solution of 5-hydroxymethyl-1,4-benzodioxan (8.0 g, 48 mmol) in dichloromethane (200 mL) was added two droplets of N,N-dimethylformamide and thionyl chloride (5.0 mL, 68 mmol) at room temperature. After the resulting solution was boiled under reflux for 1 h and subsequently cooled to room temperature water (100 mL) was added. The phases were separated and the organic phase was dried (MgSO4) and the solvents evaporated in vacuo. A solution of the remaining oil (8.5 g, 46 mmol) was added to a mixture of sodium cyanide (5.0 g, 102 mmol) and N,N-dimethylformamide (100 mL) at room temperature. After stirring for 16 h at room temperature ice was added and the resulting slurry was extracted with diethyl ether (2×250 mL). The collected organic phases were washed with saturated calcium chloride, dried (Na2SO4) and the solvents were evaporated in vacuo. A mixture of the remaining oil (6.0 g, 34 mmol), ethanol (200 mL), sodium hydroxide (6.0 g) and water (6 mL) was boiled under reflux for 16 h. After evaporation of the solvents in vacuo, water (200 mL) was added and the resulting slurry was extracted with diethyl ether (2×200 mL). The collected organic phases were washed with brine, dried (Na2SO4) and the solvents were evaporated in vacuo affording 4.0 g (43%) of the title compound as an oil: 1H NMR (CDCl3) δ 3.65 (s, 2H), 4.15-4.30 (m, 4H), 6.70-6.85 (m, 3H).

Provenance & Evidence