5-bromo-2,4-dimethoxybenzaldehyde

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: Ex-6A: 5-Bromo-2,4-dimethoxybenzaldehyde (4.9 g, 20.0 mmol) was dissolved in ethylene glycol dimethyl ether (50 mL). Tetrakis(triphenylphosphine)palladium(0) (2.32 g, 2 mmol) was added, and the mixture was stirred at room temperature under nitrogen for 5 min. Benzo[b]thiophene-2-boronic acid (4.27 g, 24 mmol) and sodium carbonate solution (2 M, 20 mL) were added. The mixture was stirred at reflux under nitrogen for 24 hours. Upon cooling to room tempaerature, it was poured into water and extracted with ethyl acetate. The organic phase was dried over sodium sulfate and evaporated. Silica gel chromatography (hexane/ethyl acetate 2:1 then 1:1) gave 4.75 g (83%) of the desired 5-(benzo[b]thien-2-yl)-2,4-dimethoxybenzaldehyde. The mixture was stirred at reflux under nitrogen for 24 hours Upon cooling to room tempaerature, it extracted with ethyl acetate The organic phase was dried over sodium sulfate evaporated

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

Procedure: Ex-44A: A solution of 5-bromo-2,4-dimethoxybenzaldehyde (1.90 g, 7.77 mmol) and trans-dichlorobis(triphenylphosphine)palladium(II) in dioxane (150 mL) was treated with 1-methyl-2-(tributylstannyl)-1H-pyrrole and then refluxed for 68 h. The reaction mixture was quenched with 10% potassium fluoride/ether (300 mL/100 mL) and filtered through Celite. The organic phase was extracted with saturated ammonium chloride solution (4×25 mL), dried over magnesium sulfate, and concentrated to a brown solid. The solid was purified by column chromatography (30% ethyl acetate/hexane) to yield 0.87 g (46%) of 2,4-dimethoxy-5-(1-methyl-1H-pyrrol-2-yl)benzaldehyde as a white solid. 1H-NMR (300 MHz, CDCl3) δ 10.34 (s, 1 H), 7.78 (s, 1H), 6.72 (m, 1H), 6.51 (s, 1H), 6.20 (m, 1H), 6.13 (m, 1H), 4.01 (s, 3H), 3.92 (s, 3H), 3.46 (s, 3H). refluxed for 68 h The reaction mixture was quenched with 10% potassium fluoride/ether (300 mL/100 mL) filtered through Celite The organic phase was extracted with saturated ammonium chloride solution (4×25 mL) dried over magnesium sulfate concentrated to a brown solid The solid was purified by column chromatography (30% ethyl acetate/hexane)

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

Procedure: Ex-32A: 2-(5-Formyl-2,4-dimethoxyphenyl)indole-l-carboxylic acid tert-butyl ester was prepared from 5-bromo-2,4-dimethoxybenzaldehyde and N-Boc-indole-2-boronic acid in a similar manner as Ex-1A, 79% yield, yellow oil. 1H-NMR (300 MHz, CDCl3) δ 10.36 (s, 1H), 8.15 (d, J=8 Hz, 1H), 7.88 (s, 1H), 7.45 (d, J=8 Hz, 3H), 7.27–7.35 (m, 1H), 7.19–7.27 (m, 1H), 6.52 (s, 1H), 6.47 (s, 1H), 4.00 (s, 3H), 3.86 (s, 3H), 1.42 (s, 9H).