Water ethanol → bicyclo[2.1.1]hexane-4-carboxylic acid

Temperature

130 °C

A mixture of 2-oxobicyclo[2.2.1]heptan-1-yl trifluoromethanesulfonate (4.6 g, 18.1 mmol) in 600 mL ethanol/water (60% w/w) and TEA (3.7 g, 36.2 mmol) was heated at 130° C. for 100 h. The mixture was concentrated under reduced pressure and the residue was poured into aqueous hydrochloric acid solution (1 mol/L, 150 mL) and extracted with diethyl ether (3×100 mL). The combined extracts were washed with brine (100 mL) and dried over anhydrous sodium sulfate. The solution was concentrated under reduced pressure to give the crude product which was purified by silica gel column chromatography (10% ethyl acetate in petroleum ether) to give the desired product (1.00 g, 8.09 mmol, yield: 45%). 1H NMR (400 MHz, CDCl3) δ ppm 2.47-2.45 (m, 1H), 1.94-1.90 (m, 4H), 1.79-1.74 (m, 2H), 1.37-1.35 (m, 2H).

1. concentrationThe mixture was concentrated under reduced pressure
2. additionthe residue was poured into aqueous hydrochloric acid solution (1 mol/L, 150 mL)
3. extractionextracted with diethyl ether (3×100 mL)
4. washThe combined extracts were washed with brine (100 mL)
5. dry with materialdried over anhydrous sodium sulfate
6. concentrationThe solution was concentrated under reduced pressure
7. customto give the crude product which
8. customwas purified by silica gel column chromatography (10% ethyl acetate in petroleum ether)

ORD record

ord-787bc7b807ee455186b9ca98e993ff27

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09139534B2