反应详情

To a suspension of methyl 8-bromo-4H-thieno[3,2-c]chromene-2-carboxylate 2 (2.64 g, 8.12 mmol, 1 equiv) in 4:1 tetrahydrofuran/water (80 mL) was added aqueous potassium hydroxide (24 mL, 24 mmol, 3.0 equiv, 1.0 M solution in water) at 24° C. After 15 hr, the tetrahydrofuran was removed in vacuo (<20 mm Hg). The resulting aqueous suspension was diluted with water until all the solids were dissolved. To the resulting solution was added concentrated hydrochloric acid until the solution reached pH=1. The resulting solids were collected by filtration and dried in vacuo (<1 mm Hg) to afford 3bp as a yellow solid (2.36 g, 93%). 1H NMR (500 MHz, CDCl3), δ: 13.28 (br s, 1H), 7.64 (d, J=2.4 Hz, 1H), 7.60 (s, 1H), 7.40 (dd, J=8.7, 2.4 Hz, 1H), 6.94 (d, J=8.7 Hz, 1H), 5.30 (s, 3H).

1. customthe tetrahydrofuran was removed in vacuo (<20 mm Hg)
2. additionThe resulting aqueous suspension was diluted with water until all the solids
3. dissolutionwere dissolved
4. additionTo the resulting solution was added concentrated hydrochloric acid until the solution
5. filtrationThe resulting solids were collected by filtration
6. customdried in vacuo (<1 mm Hg)