Ethanol → Ethyl 2-(2-oxocyclopentyl)acetate

To a solution of 2-(2-oxocyclopentyl)acetic acid (23.6 g, 166 mmol) in absolute ethanol (400 mL) was added H2SO4 (16.28 g, 166 mmol). The resultant solution was heated under reflux overnight. The reaction mixture was concentrated and the liquid residue was added into ice-water (200 mL). The aqueous mixture was extracted with DCM (3×200 mL). The combined organic layers were washed with H2O (300 mL), brine (300 mL), dried over Na2SO4, decanted, concentrated and dried under vacuum to afford the title compound as a light yellow liquid (27.2 g). LCMS m/z=171.3 [M+H]+; 1H NMR (400 MHz, CDCl3) δ ppm 1.19 (t, J=7.14 Hz, 3H), 1.50-1.62 (m, 1H), 1.65-1.80 (m, 1H), 1.92-2.02 (m, 1H), 2.12 (dd, J=16.7, 8.86 Hz, 1H), 2.19-2.29 (m, 2H), 2.30-2.44 (m, 2H), 2.65 (dd, J=15.12, 2.6 Hz, 1H), 4.07 (q, J=7.14 Hz, 2H).

1. temperatureunder reflux overnight
2. concentrationThe reaction mixture was concentrated
3. additionthe liquid residue was added into ice-water (200 mL)
4. extractionThe aqueous mixture was extracted with DCM (3×200 mL)
5. washThe combined organic layers were washed with H2O (300 mL), brine (300 mL)
6. dry with materialdried over Na2SO4
7. customdecanted
8. concentrationconcentrated
9. customdried under vacuum

ORD record

ord-6bd3ad0f82904659b8cb518d20907bf1

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09126932B2