Ethanol → Ethyl 3-Cyclopentene-1-carboxylate

To a stirred solution of cyclopent-3-enecarboxylic acid (10 g, 89.3 mmol) in anhydrous ethanol (30 mL) was added sulfurous dichloride (15.9 g, 134 mmol) at 0° C. The reaction mixture was stirred at room temperature overnight and then concentrated. The residue was poured into water. The resulting mixture was extracted with ethyl acetate (3×100 mL). The combined organic layers were washed with brine, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated and the residue was purified by silica gel column chromatography (2.5% ethyl acetate in petroleum ether) to give the desired product (6.7 g, 47.9 mmol, yield=54%) as a yellow oil which was used in the next step without further purification. 1H NMR (400 MHz, CDCl3) δ ppm 5.66 (s, 2H), 4.18-4.10 (m, 2H), 3.16-3.05 (m, 2.66 (s, 2H), 2.63 (s, 2H), 1.29-1.24 (t, J=9.4, 3H).

1. concentrationconcentrated
2. additionThe residue was poured into water
3. extractionThe resulting mixture was extracted with ethyl acetate (3×100 mL)
4. washThe combined organic layers were washed with brine
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationThe filtrate was concentrated
8. customthe residue was purified by silica gel column chromatography (2.5% ethyl acetate in petroleum ether)

ORD record

ord-371479fd040041c9bb28b588da2a3dc2

Source dataset

uspto-grants-2015_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09139534B2