反应详情

Ethyl 3-methyl-4-hydroxy-5-tert-butyl-7-p-chlorobenzoylbenzofuran-2-carboxylate, compound 17 (0.322 g, 0.79 mmol) was suspended in a solution of potassium hydroxide (0.151 g, 2.69 mmol) in water (15 mL) and heated to reflux for 2.5 hours. The resulting solution was cooled in an ice bath and acidified with 2N HCl. The product precipitated and 3-methyl-4-hydroxy-5-tert-butyl-7-p-chlorobenoylbenzofuran-2-carboxylic acid, compound 18 was collected by filtration and allowed to air dry. mp 214°-216° C.; 1H NMR (DMSO-d6) d 1.44 (9H, s), 2.78 (3H, s), 5.78 (1H, s), 7.6 (2H, d, J=8 Hz), 7.62 (1H, s), 7.74 (2H, d, J=8 Hz).

1. temperatureheated
2. temperatureto reflux for 2.5 hours
3. temperatureThe resulting solution was cooled in an ice bath
4. customThe product precipitated
5. filtration3-methyl-4-hydroxy-5-tert-butyl-7-p-chlorobenoylbenzofuran-2-carboxylic acid, compound 18 was collected by filtration
6. customto air dry