methyl 5-bromofuran-2-carboxylate

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

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

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

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

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

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

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

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

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

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

Procedure: 2-(2-Methoxy-3-nitro-phenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 6a (3.6 g, 12 mmol), 5-bromofuran-2-carboxylic acid methyl ester (2.05 g, 10 mmol), tetrakis(triphenylphosphine)palladium (1.55 g, 0.5 mmol) and sodium carbonate (2.12 g, 20 mmol) were dissolved in 1,4-dioxane. The reaction mixture was heated to reflux for 3 hours. The reaction was monitored by TLC until the disappearance of the starting materials. The mixture was filtered and the filtrate was concentrated under reduced pressure. The residue was diluted with 30 mL of water and 50 mL of ethyl acetate. The separated organic layer was concentrated under reduced pressure and recrystallized from a solvent mixture of ethyl acetate and n-hexane to obtain the title compound 5-(2-methoxy-3-nitro-phenyl)-furan-2-carboxylic acid methyl ester 54a (500 mg, yield 18%) as a yellow solid. The reaction mixture was heated to reflux for 3 hours The mixture was filtered the filtrate was concentrated under reduced pressure The residue was diluted with 30 mL of water and 50 mL of ethyl acetate The separated organic layer was concentrated under reduced pressure recrystallized from a solvent mixture of ethyl acetate and n-hexane

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

Procedure: Methyl 5-bromo-2-furancarboxylate (1.49 g) was treated with 3-[(5-bromopentyl)oxy]-1-propyne (1.49 g) according to the method of Intermediate 9 to give the title compound as a yellow oil (0.97 g), t.l.c. (cyclohexane-diethyl ether 10:1) Rf 0.18.

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