Potassium Hydroxide → 5-Norbornene-2-carboxylic acid

67.0 g (269 mmol) of the Diels-Alder adduct was dissolved in 1040 ml of a mixture solvent of tetrahydrofuran-water (5:2), 70.5 g (1.08 mol) of potassium hydroxide (85%) in 300 ml of water was added on ice cooling, and the mixture was stirred at room temperature for 24 hours. After distilling out tetrahydrofuran, the product was neutralized with 94 ml of concentrated hydrochloric acid and extracted with a mixture solvent of hexane-methylene chloride (98:2) (200 ml×4). The extract was dried on anhydrous magnesium sulfate, the solution was filtered, and the solvent was distilled off to obtain 38.8 g of crude 5-norbornene-2-carboxylic acid. Crude yield: 100%.

1. additionwas added on ice cooling
2. distillationAfter distilling out tetrahydrofuran
3. extractionextracted with a mixture solvent of hexane-methylene chloride (98:2) (200 ml×4)
4. dry with materialThe extract was dried on anhydrous magnesium sulfate
5. filtrationthe solution was filtered
6. distillationthe solvent was distilled off

ORD record

ord-5b97708d54a6469088360f4acddde66a

Source dataset

uspto-grants-1993_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05266728