Ethynyltributyltin → ethyl 6-chloro-7-(4-ethynyl-2-methylphenoxy)-2-(trifluoromethyl)-2H-chromene-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 0.28 g (0.52 mmol) of ethyl 6-chloro-7-(2-methyl-4-iodophenoxy)-2-(trifluoromethyl)-2H-chromene-3-carboxylate and 12 mg (0.0104 mmol) of tetrakistriphenylphosphine-palladium in 3.5 mL of anhydrous toluene was added 168 uL (0.586 mmol) of tributyl(ethynyl)tin. The resulting solution was heated to 110° C. and shaken for three hrs. LC-MS indicated that the reaction was complete. After cooling to room temperature, the reaction was quenched with addition of 20% aqueous ammonium fluoride. The product was extracted with ethyl acetate. The organic phase was separated and washed with brine, dried over anhydrous magnesium sulfate. After removing the volatiles, the residues were purified by silica gel chromatography with EtOAc/hexane (1:9). The product was carried on to the next step.

Provenance & Evidence