Hydrochloric Acid → HCID 67315022, compound

Participants

Reaction Steps

A solution of 5-fluoro-1,3-dihydro-indol-2-one (3.38 g, 22.4 mmol.) in THF (100 mL) is treated with a solution of lithium bis(trimethylsilyl)amide (45 mL of a 1 M solution in THF, 45 mmol) dropwise. The resulting solution is stirred at room temperature for 15 min and then treated with 2-vinyl-7H-furo[3,4-b]pyridin-5-one (1.2 g, 7.45 mmol) in one portion. The reaction mixture is stirred at room temperature for 2 h. The reaction mixture is poured into a cold aqueous 2 N HCl solution (200 mL). The ice bath is removed and the reaction mixture is heated at 50° C. for 2 h and then stirred at room temperature overnight. The reaction mixture is treated with 100 mL ice water and stirred for 30 min. The yellow solid is collected by filtration and dried. The solid is purified by chromatography (silica gel, MeOH-Chloroform) and the product containing fractions concentrated. The residue is triturated with MeOH and the solid is collected by filtration and dried to give 5-Fluoro-3-(2-vinyl-7H-furo[3,4-b]pyridin-5-ylidene)-1,3-dihydro-indol-2-one (Example 6) as an orange solid (0.82 g, 37%). The filtrate is absorbed to silica gel and subjected to chromatography (silica gel, EtOAc-hexane) to afford (Example 28) as a yellow solid (50 mg, 1.5%).

Provenance & Evidence