Iodoethane → 5-Ethylthiophene-2-carboxylic acid

Temperatur

-78 °C

A solution of thiophencarboxylic acid (4.00 g, 30.9 mmol) in THF (24 mL) is added dropwise via a syringe to a stirred solution of LDA (32.5 mL, 2 M in toluene) in THF (40 mL) cooled to −78° C. The temperature of the reaction is maintained at −78° C. for 10 min before iodoethane (4.87 g, 30.9 mmol) is added. The mixture is stirred at −78° C. for 1 h and is then allowed to warm to rt overnight. The reaction is quenched by the addition of water. The mixture is acidified and extracted three times with diethyl ether. The org. extracts are dried over MgSO4, filtered and evaporated. The crude product is purified by MPLC on reversed phase silica gel to give the title compound (1.10 g) as a brownish solid; LC-MS: tR=0.80 min, 1H NMR (CDCl3): δ 1.34 (t, J=7.3 Hz, 3H), 2.90 (q, J=7.6 Hz, 2H), 6.84 (d, J=3.5 Hz, 1H), 7.73 (d, J=3.8 Hz, 1H).

1. additionis added
2. temperatureto warm to rt overnight
3. customThe reaction is quenched by the addition of water
4. extractionextracted three times with diethyl ether
5. dry with materialextracts are dried over MgSO4
6. filtrationfiltered
7. customevaporated
8. customThe crude product is purified by MPLC on reversed phase silica gel

ORD-Eintrag

ord-59db637faf344519ab602f6a5a881349

Quelldatensatz

uspto-grants-2012_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08133910B2