HCID 12747901, compound → HCID 12747909, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of (±)methyl-6,7-dichloro-2,3-dihydro-5-(2-thenoyl)benzofuran-2-carboxylate (3.57 g., 0.01 mole) in tetrahydrofuran (50 ml.) at -70° C. is added a solution of "Red-Al" (1.5 g., 0.0107 mole) in tetrahydrofuran (10 ml.) over a ten minute period. The reaction solution is stirred one hour at -70° C. and then quenched with 20% sulfuric acid (10 ml.). The water layer is separated and extracted twice with tetrahydrofuran (10 ml.). The organic layers are combined, washed with brine (two 5 ml. portions), dried over magnesium sulfate and the tetrahydrofuran distilled at reduced pressure. The residue is dissolved in n-butyl chloride (50 ml.) and added to a solution of sodium bisulfite (6 g.) in warm water (10 ml.). The mixture is stirred overnight before the solid bisulfite addition product is added to a saturation sodium bicarbonate solution (25 ml.) and stirred for two hours at room temperature. The mixture is extracted with ether (2×50 ml.). The ether extracts are washed with brine (2×25 ml.), dried over MgSO4 and evaporated in vacuo to give the (±)-6,7-dichloro-2,3-dihydro-5-(2-thenoyl)benzofuran-2-carboxaldehyde which melts at 162°-4° C.

Provenance & Evidence