Potassium Hydroxide → HCID 57900438, compound

Participants

Reaction Steps

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, 1 H), 7.64 (d, J=2.4 Hz, 1 H), 7.60 (s, 1 H), 7.40 (dd, J=8.7, 2.4 Hz, 1 H), 6.94 (d, J=8.7 Hz, 1 H), 5.30 (s, 3 H).

Provenance & Evidence