Ethyl levulinate → HCID 49840280, compound

3-Bromo-2,2′-bithiophene (1.00 g, 4.08 mmol) in dry diethylether (35 mL) was added slowly to a solution of n-butyllithium (1.6 M in hexane, 2.50 mL, 4.08 mmol) in dry diethylether (35 mL) at −78° C. over 2 h under N2. The mixture was stirred for 15 minutes at the same temperature. Freshly distilled ethyllevulinate (0.58 mL, 4.08 mmol) was added to the mixture at −78° C., followed by stirring overnight at room temperature. The reaction was quenched with an aqueous NH4Cl-solution (2.5 M, 20 mL) and water (80 mL) at 0° C. The organic phase was separated and the aqueous phase was extracted with diethylether. The combined organic phases were washed with brine, dried over MgSO4 and evaporated under reduced pressure to give a crude oil. The oily residue was purified by gradient column chromatography (eluent hexane/EtOAc 95:5) to afford the title compound as a yellow oil (0.35 g, 28%). 1H-NMR (CDCl3): δ=7.38 (dd, J=5.1 Hz, J=1.3 Hz, 1H), 7.27 (d, J=5.3 Hz, 1H), 7.15 (d, J=5.3 Hz, 1H), 7.09 (dd, J=3.7 Hz, J=1.3 Hz, 1H), 7.04 (dd, J=5.1 Hz, J=3.7 Hz, 1H), 2.59-2.40 (m, 2H), 2.19-2.12 (m, 2H), 1.69 (s, 3H).

1. stirringby stirring overnight at room temperature
2. customThe reaction was quenched with an aqueous NH4Cl-solution (2.5 M, 20 mL) and water (80 mL) at 0° C
3. customThe organic phase was separated
4. extractionthe aqueous phase was extracted with diethylether
5. washThe combined organic phases were washed with brine
6. dry with materialdried over MgSO4
7. customevaporated under reduced pressure
8. customto give a crude oil
9. customThe oily residue was purified by gradient column chromatography (eluent hexane/EtOAc 95:5)

ORD record

ord-a7a7dafc36a944549e485666df679eec

Source dataset

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08329923B2