Water → 2-Methylthiophene-3-carboxylic acid

3-Thiophenecarboxylic acid (3.84 g) was dissolved in tetrahydrofuran (50 ml), and the mixture was cooled to -78° C. n-Butyllithium (1.6M in hexane, 41.3 ml) was slowly added dropwise, and the mixture was stirred at the same temperature for 30 minutes. Iodomethane (3.7 ml) in tetrahydrofuran (10 ml) was added dropwise. The resulting mixture was heated to room temperature and stirred for 15 hours. The mixture was poured into water and washed with diethyl ether. The aqueous layer was acidified with 1N hydrochloric acid, and extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give 2-methyl-3-thiophenecarboxylic acid (3.98 g) as crystals.

1. additionwas slowly added dropwise
2. stirringstirred for 15 hours
3. washwashed with diethyl ether
4. extractionextracted with ethyl acetate
5. dry with materialThe extract was dried over anhydrous magnesium sulfate
6. concentrationconcentrated under reduced pressure

ORD-Eintrag

ord-da6a2587c0d640abab32aafb95f4461a

Quelldatensatz

uspto-grants-1998_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05840917