反应详情

To a solution of potassium hydroxide (1.96 g, 34.86 mmol) in water (75 mL) was added compound 1 (4.00 g, 11.62 mmol) and the resulting suspension was heated to reflux for two hours. During the reflux a small portion of methanol was rinsed into the reaction mixture. After cooling, the reaction mixture was diluted with water (225 mL) and acidified with 2N HCl (25 mL). The resulting suspension was cooled in an ice bath, and the product collected by filtration. After vacuum drying, 3-methyl-4-methoxy-7-(2-thienoyl)-benzofuran-2-carboxylic acid, compound 2, was obtained. mp 252°-255° C.; 1H NMR d 2.80 (3H, s), 2.80 (1H, br s), 4.06 (3H, s), 6.76 (1H, d, J=8 Hz), 7.19 (1H, m), 7.70 (1H, dd, J=4 Hz, 1 Hz), 7.76 (1H, dd, J=4 Hz, 1 Hz), 7.90 (1H, d, J=8 Hz).

1. temperaturethe resulting suspension was heated
2. temperatureto reflux for two hours
3. washwas rinsed into the reaction mixture
4. temperatureAfter cooling
5. additionthe reaction mixture was diluted with water (225 mL)
6. temperatureThe resulting suspension was cooled in an ice bath
7. filtrationthe product collected by filtration
8. customAfter vacuum drying