3-bromo-6-hydroxy-2-methylbenzaldehyde

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 3-Bromo-6-hydroxy-2-methyl-benzaldehyde (6.8 g, 0.032 mol)) in anhydrous DMF (50 ml) was added potassium carbonate (13.1 g, 0.095 mol) and cooled to 0° C. Bromo ethyl acetate (7.1 ml, 0.063 mol) was added slowly. The reaction mixture was stirred for one hour at 0° C. The completion of the reaction was confirmed by TLC. The reaction mixture was then heated to 100° C. and maintained for 2 hours. After cooling to room temperature, ice water (250 ml) was added and the mixture was stirred for 20 minutes. The solid separated was filtered, washed with water (100 ml) and dried under vacuum, to get crude product. Column chromatography using 2/5 ethyl acetate/hexane yielded 5-Bromo-4-methyl-benzofuran-2-carboxylic acid ethyl ester (6.2 g, 69.6%) The reaction mixture was then heated to 100° C. maintained for 2 hours After cooling to room temperature the mixture was stirred for 20 minutes The solid separated was filtered washed with water (100 ml) dried under vacuum to get crude product

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of boron tribromide (12.62 ml, 0.087 mol) in dichloromethane (50 ml) was added to a stirred solution of 3-Bromo-6-methoxy-2-methyl-benzaldehyde (20.0 g, 0.087 mol) in dichloromethane (350 ml) under nitrogen at 0° C. The reaction mixture was stirred for 1.5 hours. Water (400 ml) was added cautiously and the mixture was stirred for 15 min. The organic layer was washed with sodium bicarbonate solution (200 ml), water (200 ml) and brine (200 ml). The organic layer was dried over sodium sulfate and concentrated under reduced pressure to give the crude product as orange brown solid. Column chromatography using 3/97 ethyl acetate/hexane yielded 3-Bromo-6-hydroxy-2-methyl-benzaldehyde (13.82 g, 73.6%). the mixture was stirred for 15 min The organic layer was washed with sodium bicarbonate solution (200 ml), water (200 ml) and brine (200 ml) The organic layer was dried over sodium sulfate concentrated under reduced pressure to give the crude product as orange brown solid