2-Thiophenecarboxaldehyde, 5-chloro- → 2-(5-Chlorothiophen-2-yl)ethenesulfonic acid ethyl ester

Temperatur

50 °C

n-Butyllithium (53.1 mL, 2.5M solution in hexanes) is added dropwise to a solution of ethylmethanesulfonate (12.9 mL, 0.12 mol) in THF (300 mL) at −78° C. The reaction mixture is stirred for 15 min then ethylchlorophosphonate (9.9 mL, 0.07 mol) is added dropwise. The solution is stirred at −78° C. for 30 minutes and then heated to 50° C. for 1 hour. The reaction mixture is then cooled to −78° C. and stirred for 1 h then 5-chlorothiophenecarboxaldehyde (7.1 mL, 0.07 mol) is added dropwise. The reaction mixture is allowed to slowly warm to RT overnight. Water (30 mL) is added to the mixture and stirred for 15 min then concentrated in vacuo. The residue is taken up in CH2Cl2 and washed with water, brine, dried over MgSO4, filtered and concentrated to dryness. The crude product is purified by column chromatography eluting with 5% EtOAc/hexanes to give title product (11.3 g, 0.04 mol) as an oil. 1H NMR (CDCl3, 300 MHz) δ7.51 (d, 1H), 7.10 (d, 1H), 6.91 (d, 1H), 6.42 (d, 1H), 4.20 (q, 2H), 1.40 (t, 3H).

1. stirringThe solution is stirred at −78° C. for 30 minutes
2. temperatureThe reaction mixture is then cooled to −78° C.
3. stirringstirred for 1 h
4. temperatureto slowly warm to RT overnight
5. stirringstirred for 15 min
6. concentrationthen concentrated in vacuo
7. washwashed with water, brine
8. dry with materialdried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated to dryness
11. customThe crude product is purified by column chromatography
12. washeluting with 5% EtOAc/hexanes

ORD-Eintrag

ord-7ba1099762a64f9bbf91a42c5dc6f48c

Quelldatensatz

uspto-grants-2009_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07612075B2