5-Methyl-2-thiophenecarboxaldehyde → 2-(5-Methyl-thiophen-2-yl)-ethenesulfonic acid, ethyl ester

n-Butyl lithium (1.6 mL of a 2.5 M solution in hexanes, 4.0 mmol) was added dropwise to a solution of ethyl diethylphosphorylmethanesulfonate (1.0 g, 3.8 mmol), prepared as described in Tetrahedron, 1987, 43(21), 5125, at −78° C. in THF (15 mL). The mixture was stirred for 20 min. then 5-methyl-2-thiophenecarboxaldehyde (460 mg, 4.2 mmol) was slowly added. The mixture was stirred at −78° C. for 1 h. then allowed to warm to room temperature overnight. The bulk of the solvents were evaporated and the residue was treated with water (2 mL) and extracted with CH2CL2. The organic layer was washed with brine, dried over MgSO4, filtered and concentrated. The crude product was purified by column chromatography eluting with CH2CL2 to give the title compound.

1. customprepared
2. stirringThe mixture was stirred at −78° C. for 1 h.
3. customThe bulk of the solvents were evaporated
4. additionthe residue was treated with water (2 mL)
5. extractionextracted with CH2CL2
6. washThe organic layer was washed with brine
7. dry with materialdried over MgSO4
8. filtrationfiltered
9. concentrationconcentrated
10. customThe crude product was purified by column chromatography
11. washeluting with CH2CL2

ORD record

ord-b98ce9f1c2404cf5a93cb1f2ee732d58

Source dataset

uspto-grants-2003_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06555542B1