Ethyl 2-thienylacetate → 1-Thiophen-2-yl-cyclopent-3-ene carboxylic acid ethyl ester

To a solution of thiophen-2-yl acetic acid ethyl ester (1) (980 mg, 5.76 mmol) in 10 ml of THF at -20° C. was added a 1M solution of potassium t-butoxide in THF (5.76 ml, 5.76 mM) over 15 minutes. After 30 minutes at -20° C., cis-1,4-dichlorobut-2-ene (0.610 ml, 5.76 mmol) was added dropwise and the reaction was warmed to room temperature. After 20 minutes the reaction was recooled to -20° C. and treated with potassium t-butoxide in THF (5.76 ml, 5.76 mM). The reaction was allowed to warm to room temperature, then was heated at 50° C. for 30 minutes and quenched with saturated ammonium chloride solution. The solvents were removed in vacuo and the residue taken up in EtOAc and washed with water. The organic layer was washed with saturated sodium chloride and dried over MgSO4 to yield the title compound (2) (450 mg) after chromatography on silica gel using 5% EtOAc in hexanes as the eluant.

1. waitAfter 20 minutes the reaction was recooled to -20° C.
2. temperatureto warm to room temperature
3. temperaturewas heated at 50° C. for 30 minutes
4. customquenched with saturated ammonium chloride solution
5. customThe solvents were removed in vacuo
6. washwashed with water
7. washThe organic layer was washed with saturated sodium chloride
8. dry with materialdried over MgSO4

ORD record

ord-447f2289eef446f296b6a0f2ffe9e0b7

Source dataset

uspto-grants-1998_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05789415