Potassium Fluoride → 1,1'-(4H-thieno[3,2-c]chromene-2,7-diyl)diethanone

Participants

Reaction Steps

A solution of 1-(7-bromo-4H-thieno[3,2-c]chromen-2-yl)ethanone (1b) (14 g, 45.3 mmol) in 300 ml of anhydrous dioxane was degassed by passing nitrogen gas for 45 min. Tributyl(1-ethoxyvinyl)stannane (16.35 g, 45.3 mmol) was added to it followed by Pd(PPh3)4 (4.19 g, 3.62 mmol) and PdCl2(dppf)-CH2Cl2 adduct (2.65 g, 3.62 mmol) and the solution was heated at 90 OC for overnight. After cooling, the volume of dioxane was reduced, and a saturated solution of KF was added to it and stirred for 15 min., after which the mixture was passed through a pad of celite and washed with ethyl acetate. The combined filtrate was stirred with 4N HCl solution for 1 h and the organic layer was dried over Na2SO4, filtered and concentrated. The residue was purified by column chromatography to obtain the diacetyl compound (1c) (11.5 g, 68%). m/z 272.9 (M+H)+.

Provenance & Evidence