Iodine → 4-Fluoro-7-methoxy-1-benzothiophene-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

(2Z)-3-(2-Fluoro-5-methoxyphenyl)-2-mercapto-2-propenoic acid (1.00 g, 4.38 mmol) was added in one portion to a solution of iodine (1.66 g, 6.56 mmol) in dimethoxyethane (10 mL). This was heated in the microwave with 300 W at 160° C. for 10 mins. After this time the reaction was allowed to cool to room temperature and poured onto saturated sodium metabisulphite (200 mL) and ether (400 mL). Ether layer was separated and product extracted with aqueous sodium hydroxide (2 N, 2×100 mL). This was then acidified to pH 2 with aqueous hydrochloric acid (2 N, 250 mL), and product extracted with ether (2×150 mL). The combined organic extracts were dried (MgSO4) and concentrated in vacuo to give a white solid (580 mg, 30%); δH (300 MHz, CD3OD) 8.00 (1H, s, Ar), 7.30–7.19 (1H, m, Ar), 7.10–7.00 (1H, m, Ar), 3.95 (3H, s, OCH3).

Provenance & Evidence