ethyl 3-bromofuran-2-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: Ethyl 3-bromofuran-2-carboxylate (296 mg, 1.35 mmol) obtained in Step 1 of Reference Example 29, 4-(tri-n-butylstannyl)pyridine (550 mg, 1.51 mmol) and tetrakis(triphenylphosphine)palladium(0) (157 mg, 0.136 mmol) were dissolved in THF (10 mL), followed by stirring under heating and reflux for 4 hours. Aqueous ammonium fluoride solution was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and then the solvent was distilled away under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3) to afford ethyl 3-(4-pyridyl)furan-2-carboxylate (133 mg, 45%). under heating reflux for 4 hours followed by extraction with ethyl acetate The organic layer was dried over anhydrous magnesium sulfate the solvent was distilled away under reduced pressure The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3)

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3-Bromofuran-2-carboxylic acid (1.86 g, 9.75 mmol), ethyl iodide (3.1 mL, 38.8 mol) and cesium carbonate (4.80 g, 14.7 mmol) were suspended in acetonitrile (50 mL), followed by stirring at 80° C. for 3 hours. Aqueous saturated sodium hydrogencarbonate solution was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and then the solvent was distilled away under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=9:1) to afford ethyl 3-bromofuran-2-carboxylate (1.16 g, 54%). followed by extraction with ethyl acetate The organic layer was dried over anhydrous magnesium sulfate the solvent was distilled away under reduced pressure The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=9:1)

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (4-sulfamoylphenyl)boronic acid (1.76. gm, 8.77 mmol) and Potassium carbonate (2.52 gm, 18.26 mmol) were added to a stirred suspension of ethyl 3-bromofuran-2-carboxylate (Prepared according to the procedure reported in the literature EP1489077A1, 2004, 1.6 gm, 7.30 mmol) in a mixture of 80 ml of ethanol and 20 ml of toluene (80 ml:20 ml) under nitrogen atmosphere at room temperature (25° C.) in a tube. A nitrogen gas was purged to the suspension for 15 minute at room temperature (about 25° C.). To the reaction mixture was then added Tetrakis(triphenyl phosphine)Palladium(0) (0.422 gm, 0.365 mmol) at 25° C. and tube was sealed. The reaction mixture was then stirred at 100° C. for 18 hours. The progress of the reaction was monitored by TLC. The reaction mixture was then filtered and washed with ethyl acetate (2×100 ml). The combined organic layer was then concentrated under reduced pressure to obtain a crude product as semi-solid (11.2 gm), which was then purified by column chromatography over silica gel (100-200 mesh) using 50% ethyl acetate in hexanes as an eluent to obtain the title compound (1.2 g, 55.60%) Prepared A nitrogen gas was purged to the suspension for 15 minute at room temperature (about 25° C.) The reaction mixture was then filtered washed with ethyl acetate (2×100 ml) The combined organic layer was then concentrated under reduced pressure to obtain a crude product as semi-solid (11.2 gm), which was then purified by column chromatography over silica gel (100-200 mesh)

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

Procedure: Ethyl 3-bromofuran-2-carboxylate (296 mg, 1.35 mmol) obtained in Step 1 of Reference Example 29, 4-(tri-n-butylstannyl)pyridine (550 mg, 1.51 mmol) and tetrakis(triphenylphosphine)palladium(0) (157 mg, 0.136 mmol) were dissolved in THF (10 mL), followed by stirring under heating and reflux for 4 hours. Aqueous ammonium fluoride solution was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and then the solvent was distilled away under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3) to afford ethyl 3-(4-pyridyl)furan-2-carboxylate (133 mg, 45%). under heating reflux for 4 hours followed by extraction with ethyl acetate The organic layer was dried over anhydrous magnesium sulfate the solvent was distilled away under reduced pressure The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3)

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

Procedure: Ethyl 3-bromofuran-2-carboxylate (296 mg, 1.35 mmol) obtained in Step 1 of Reference Example 29, 4-(tri-n-butylstannyl)pyridine (550 mg, 1.51 mmol) and tetrakis(triphenylphosphine)palladium(0) (157 mg, 0.136 mmol) were dissolved in THF (10 mL), followed by stirring under heating and reflux for 4 hours. Aqueous ammonium fluoride solution was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and then the solvent was distilled away under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3) to afford ethyl 3-(4-pyridyl)furan-2-carboxylate (133 mg, 45%). under heating reflux for 4 hours followed by extraction with ethyl acetate The organic layer was dried over anhydrous magnesium sulfate the solvent was distilled away under reduced pressure The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3)

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3-Bromofuran-2-carboxylic acid (1.86 g, 9.75 mmol), ethyl iodide (3.1 mL, 38.8 mol) and cesium carbonate (4.80 g, 14.7 mmol) were suspended in acetonitrile (50 mL), followed by stirring at 80° C. for 3 hours. Aqueous saturated sodium hydrogencarbonate solution was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and then the solvent was distilled away under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=9:1) to afford ethyl 3-bromofuran-2-carboxylate (1.16 g, 54%). followed by extraction with ethyl acetate The organic layer was dried over anhydrous magnesium sulfate the solvent was distilled away under reduced pressure The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=9:1)

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3-Bromofuran-2-carboxylic acid (1.86 g, 9.75 mmol), ethyl iodide (3.1 mL, 38.8 mol) and cesium carbonate (4.80 g, 14.7 mmol) were suspended in acetonitrile (50 mL), followed by stirring at 80° C. for 3 hours. Aqueous saturated sodium hydrogencarbonate solution was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and then the solvent was distilled away under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=9:1) to afford ethyl 3-bromofuran-2-carboxylate (1.16 g, 54%). followed by extraction with ethyl acetate The organic layer was dried over anhydrous magnesium sulfate the solvent was distilled away under reduced pressure The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=9:1)

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

Procedure: Ethyl 3-bromofuran-2-carboxylate (296 mg, 1.35 mmol) obtained in Step 1 of Reference Example 29, 4-(tri-n-butylstannyl)pyridine (550 mg, 1.51 mmol) and tetrakis(triphenylphosphine)palladium(0) (157 mg, 0.136 mmol) were dissolved in THF (10 mL), followed by stirring under heating and reflux for 4 hours. Aqueous ammonium fluoride solution was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and then the solvent was distilled away under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3) to afford ethyl 3-(4-pyridyl)furan-2-carboxylate (133 mg, 45%). under heating reflux for 4 hours followed by extraction with ethyl acetate The organic layer was dried over anhydrous magnesium sulfate the solvent was distilled away under reduced pressure The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3)

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

Procedure: Ethyl 3-bromofuran-2-carboxylate (296 mg, 1.35 mmol) obtained in Step 1 of Reference Example 29, 4-(tri-n-butylstannyl)pyridine (550 mg, 1.51 mmol) and tetrakis(triphenylphosphine)palladium(0) (157 mg, 0.136 mmol) were dissolved in THF (10 mL), followed by stirring under heating and reflux for 4 hours. Aqueous ammonium fluoride solution was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and then the solvent was distilled away under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3) to afford ethyl 3-(4-pyridyl)furan-2-carboxylate (133 mg, 45%). under heating reflux for 4 hours followed by extraction with ethyl acetate The organic layer was dried over anhydrous magnesium sulfate the solvent was distilled away under reduced pressure The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3)

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

Procedure: Ethyl 3-bromofuran-2-carboxylate (296 mg, 1.35 mmol) obtained in Step 1 of Reference Example 29, 4-(tri-n-butylstannyl)pyridine (550 mg, 1.51 mmol) and tetrakis(triphenylphosphine)palladium(0) (157 mg, 0.136 mmol) were dissolved in THF (10 mL), followed by stirring under heating and reflux for 4 hours. Aqueous ammonium fluoride solution was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and then the solvent was distilled away under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3) to afford ethyl 3-(4-pyridyl)furan-2-carboxylate (133 mg, 45%). under heating reflux for 4 hours followed by extraction with ethyl acetate The organic layer was dried over anhydrous magnesium sulfate the solvent was distilled away under reduced pressure The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=2:3)

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3-Bromofuran-2-carboxylic acid (1.86 g, 9.75 mmol), ethyl iodide (3.1 mL, 38.8 mol) and cesium carbonate (4.80 g, 14.7 mmol) were suspended in acetonitrile (50 mL), followed by stirring at 80° C. for 3 hours. Aqueous saturated sodium hydrogencarbonate solution was added to the reaction mixture, followed by extraction with ethyl acetate. The organic layer was dried over anhydrous magnesium sulfate, and then the solvent was distilled away under reduced pressure. The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=9:1), to afford ethyl 3-bromofuran-2-carboxylate (1.16 g, 54%). followed by extraction with ethyl acetate The organic layer was dried over anhydrous magnesium sulfate the solvent was distilled away under reduced pressure The resulting residue was purified through silica gel column chromatography (hexane:ethyl acetate=9:1)