Hydrochloric Acid → Hexahydro-3H-benzofuran-2-one

Temperature

0 °C

2-Oxocyclohexylacetic acid (31.2 g, 200 mmol) is dissolved in 125 ml of 0.2 N aqueous sodium hydroxide solution and, at room temperature, added dropwise to a solution of sodium borohydride (18.9 g, 500 mmol) in 150 ml of 0.2 N aqueous sodium hydroxide solution. The mixture is stirred for 20 h and then cooled to 0° C. and carefully acidified with 6 N HCl. The strongly acidic solution is then heated at 100° C. for 30 min and subsequently stirred overnight. The cold mixture is then extracted with MTBE, and the combined ether phases are washed with 5% strength sodium carbonate solution and sat. NaCl solution, dried over magnesium sulphate, filtered and concentrated. Purification is carried out by distillation (b.p.: 75° C./0.01 mm). Yield: 22.9 g (81.7%). MS (CI): m/e=141 [M+H+]

1. temperatureThe strongly acidic solution is then heated at 100° C. for 30 min and subsequently stirred overnight
2. extractionThe cold mixture is then extracted with MTBE
3. washthe combined ether phases are washed with 5% strength sodium carbonate solution and sat. NaCl solution
4. dry with materialdried over magnesium sulphate
5. filtrationfiltered
6. concentrationconcentrated
7. customPurification
8. distillationis carried out by distillation (b.p.: 75° C./0.01 mm)

ORD record

ord-4fc3c65af649429ea5b88d84146e879b

Source dataset

uspto-grants-2002_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06433004B1