Sodium Hydroxide → HCID 44182001, compound

A solution of ethyl 1-ethylcyclopent-3-enecarboxylate (3.5 g, 20.8 mmol) and aqueous sodium hydroxide solution (20.8 mL, 2 mol/L) in methanol (30 mL) was stirred at 80° C. for 2 h and then concentrated. The residue was poured into water, and extracted with ether (3×100 mL). The water layer was acidified with 4 mol/L aqueous hydrochloric acid solution to pH<3, and extracted with ethyl acetate (3×100 mL). The combined organic layers were washed with brine, dried over anhydrous sodium sulfate and filtered. Concentration under reduced pressure gave the crude product, which was purified by silica gel column chromatography (5% ethyl acetate in petroleum ether) to afford the title compound (1.9 g, 13.6 mmol, 65.5% yield). 1H NMR (400 MHz, CDCl3) δ ppm 5.61 (s, 2.91 (d, J=14.8, 2H), 2.32 (d, J=14.4, 2H), 1.78-1.72 (m, 2H), 0.92-0.88 (t, J=7.4, 3H).

1. concentrationconcentrated
2. additionThe residue was poured into water
3. extractionextracted with ether (3×100 mL)
4. extractionextracted with ethyl acetate (3×100 mL)
5. washThe combined organic layers were washed with brine
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationConcentration under reduced pressure
9. customgave the crude product, which
10. customwas purified by silica gel column chromatography (5% ethyl acetate in petroleum ether)

ORD record

ord-f7372c79ef7c4341a502ba9ddbb94c4e

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09139534B2