Water → 5-Fluorothiophene-2-carboxylic acid

A mixture of the title product of Example 1 (1.5 g, 11.8 mmol) and 1.0 N NaOH (25 mL, 25 mmol) was refluxed for 3 hours. The mixture was poured into water (200 mL) and washed two times with 200 mL diethyl ether. The aqueous extract was acidified with 1N hydrochloric acid to pH 1, then extracted two times with 200 mL methylene chloride. The organic extracts were combined, washed with water (80 mL), dried (MgSO4) and concentrated in vacuo to give a solid. Trituration with hexanes afforded 1.2 g (82%) of the title product as a white solid, mp 140-2° C. 1H-NMR (d6 -DMSO): δ 7.47 (m, 1H), 6.84 (m, 1H).

1. temperaturewas refluxed for 3 hours
2. washwashed two times with 200 mL diethyl ether
3. extractionThe aqueous extract
4. extractionextracted two times with 200 mL methylene chloride
5. washwashed with water (80 mL)
6. dry with materialdried (MgSO4)
7. concentrationconcentrated in vacuo
8. customto give a solid

ORD record

ord-7503faff554640d08deeb8cddfddd00f

Source dataset

uspto-grants-2000_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06043379