methyl 4,5-dibromofuran-2-carboxylate

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of methyl 4,5-dibromo-2-furancarboxylate (4.5 g, 15.85 mmol) and BIS(TRIPHENYLPHOSPHINE)PALLADIUM(II) CHLORIDE (0.38 g, 0.541 mmol) in THF (100 mL) at RT was added chloro(methyl)zinc (15 mL, 30 mmol) dropwise. After stirring for 10 h, the reaction was quenched with NH4Cl (sat'd) (50 mL). The mixture was extracted with EtOAc (50 mL×3), and the collected organic layers were dried over MgSO4. Solvent was removed under vacuum and the resulting residue was purified via column chromatography (silica, EtOAc/Hex 10-20%) to give the title compound (2.5 g, 72%) as a white solid: LC-MS (ES) m/z 220 (M+H)+. the reaction was quenched with NH4Cl (sat'd) (50 mL) The mixture was extracted with EtOAc (50 mL×3) the collected organic layers were dried over MgSO4 Solvent was removed under vacuum the resulting residue was purified via column chromatography (silica, EtOAc/Hex 10-20%)

反応条件: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Isopropylmagnesium chloride (1.20 ml, 2.40 mmol) was added dropwise to a solution of methyl 4,5-dibromo-2-furancarboxylate (568 mg, 2.0 mmol) in Tetrahydrofuran (THF) (16 ml) at 0° C. The resulting mixture was stirred at this temperature for 30 min and then cooled to −78° C. A solution of hexylchloroethane (568 mg, 2.401 mmol) in THF (1 mL) was added dropwise, and the resulting mixture was stirred at this temperature for 1 hr. The reaction was quenched with addition of NH4Cl (sat. aq) and the resulting mixture was stirred at rt overnight. Ether and water were added and the aqueous layer was discarded. The organic layer was washed with brine, dried (Na2SO4) and concentrated to give 0.34 g of the product containing its isopropyl ester. the resulting mixture was stirred at this temperature for 1 hr The reaction was quenched with addition of NH4Cl (sat. aq) the resulting mixture was stirred at rt overnight Ether and water were added The organic layer was washed with brine dried (Na2SO4) concentrated

反応条件: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Isopropylmagnesium chloride (1.20 ml, 2.40 mmol) was added dropwise to a solution of methyl 4,5-dibromo-2-furancarboxylate (568 mg, 2.0 mmol) in Tetrahydrofuran (THF) (16 ml) at 0° C. The resulting mixture was stirred at this temperature for 30 min and then cooled to −78° C. A solution of hexylchloroethane (568 mg, 2.401 mmol) in THF (1 mL) was added dropwise, and the resulting mixture was stirred at this temperature for 1 hr. The reaction was quenched with addition of NH4Cl (sat. aq) and the resulting mixture was stirred at rt overnight. Ether and water were added and the aqueous layer was discarded. The organic layer was washed with brine, dried (Na2SO4) and concentrated to give 0.34 g of the product containing its isopropyl ester. the resulting mixture was stirred at this temperature for 1 hr The reaction was quenched with addition of NH4Cl (sat. aq) the resulting mixture was stirred at rt overnight Ether and water were added The organic layer was washed with brine dried (Na2SO4) concentrated

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Methyl 4,5-dibromo-2-furancarboxylate (3.7 g, 13.03 mmol) [prepared according to Example 127] and trans-dichlorobis(triphenylphosphine)Palladium (II) (0.46 g, 0.65 mmol) were combined in THF (50 ml) to give a yellow suspension. A THF solution of methylzinc chloride (11.40 ml, 22.81 mmol) was added dropwise at room temperature. After stirring at ambient temperature for 20 h, the solution was concentrated and purified using silica gel and eluting with 0-30% ethyl acetate/hexane to generate the title compound as a white solid (1.45 g, 6.61 mmol, 51% yield): LC-MS (ES) m/z 220 (M+H)+. to give a yellow suspension the solution was concentrated purified eluting with 0-30% ethyl acetate/hexane

反応条件: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of methyl 4,5-dibromo-2-furancarboxylate (3.3 g, 11.62 mmol) in tetrahydrofuran (46 ml) at −40° C. was added isopropylmagnesium chloride (6.97 ml, 13.95 mmol). After 1 h, Water (11 ml) was added and the solution warmed to 25° C. The reaction mixture was then partitioned between H2O-DCM and the aqueous phase was washed several times with DCM. The combined organic fractions were dried over Na2SO4, concentrated and purified by column chromatography (3% EtOAc in hexanes) affording methyl 4-bromo-2-furancarboxylate (1.4 g, 6.49 mmol, 56% yield) as a yellow solid: LCMS (ES) m/e 205, 207 (M, M+2)+. The reaction mixture was then partitioned between H2O-DCM the aqueous phase was washed several times with DCM The combined organic fractions were dried over Na2SO4 concentrated purified by column chromatography (3% EtOAc in hexanes)

反応条件: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of 4,5-dibromo-2-furancarboxylic acid (25 g, 93 mmol) in methanol (185 ml) was added sulfuric acid (24.7 ml, 463 mmol). The resulting solution stirred at 50° C. over 12 h. The solution was partitioned between H2O-DCM and the aqueous phase was washed several times with DCM. The combined organic fractions were dried over Na2SO4, concentrated and used directly without further purification providing methyl 4,5-dibromo-2-furancarboxylate (23.67 g, 83 mmol, 90% yield), LCMS (ES) m/e 283, 285, 287 (M, M+2, M+4)+. The solution was partitioned between H2O-DCM the aqueous phase was washed several times with DCM The combined organic fractions were dried over Na2SO4 concentrated used directly without further purification