2-butyl-1-benzofuran

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: A solution of 2-n-butylbenzofurane (19.8 g, 114 mmol) and 4-bromobenzoyl chloride (25.0 g, 114 mmol) in dry dichloromethane (300 mL, 0.4 M) was cooled to 0° C. and treated with AlCl3 (16.6 g, 1.1 equiv., 125.4 mmol) in 3 portions. After the additions were complete, the solution was stirred for 3 h and carefully added to ice water. After separation, the aqueous layer was extracted with dichloromethane (2×200 mL) and the combined organic layers were washed with water, sat'd aq NaCl, dried over anhydrous MgSO4, filtered and concentrated in vacuo. Purification by flash column chromatography (1-2% ethyl acetate in heptane) afforded (4-bromo-phenyl)-(2-butyl-benzofuran-3-yl)-methanone (14.6 g, 36%). After separation the aqueous layer was extracted with dichloromethane (2×200 mL) the combined organic layers were washed with water dried over anhydrous MgSO4 filtered concentrated in vacuo Purification by flash column chromatography (1-2% ethyl acetate in heptane)

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

Procedure: A solution of 2-n-butylbenzofurane (19.8 g, 114 mmol) and 4-bromobenzoyl chloride (25.0 g, 114 mmol) in dry dichloromethane (300 mL, 0.4 M) was cooled to 0° C. and treated with AlCl3 (16.6 g, 1.1 equiv., 125.4 mmol) in 3 portions. After the additions were complete, the solution was stirred for 3 h and carefully added to ice water. After separation, the aqueous layer was extracted with dichloromethane (2×200 mL) and the combined organic layers were washed with water, sat'd aq NaCl, dried over anhydrous MgSO4, filtered and concentrated in vacuo. Purification by flash column chromatography (1-2% ethyl acetate in heptane) afforded (4-bromo-phenyl)-(2-butyl-benzofuran-3-yl)-methanone (14.6 g, 36%). After separation the aqueous layer was extracted with dichloromethane (2×200 mL) the combined organic layers were washed with water dried over anhydrous MgSO4 filtered concentrated in vacuo Purification by flash column chromatography (1-2% ethyl acetate in heptane)

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

Procedure: To a solution of DMF (59 g, 0.805 mol) in anhydrous DCM (300 mL) was added slowly at 0° C. under N2 atmosphere phosphorous oxy-chloride (123 g, 0.84 mol). The mixture was stirred at rt for 2 h. To this was added slowly 2-butyl-1-benzofuran (35 g, 0.21 mol) in anhydrous DCM (100 mL). The reaction mixture was slowly heated to 60° C. for 72 h, cooled to rt and poured into ice and extracted with EtOAc. The organic layer was washed with water, brine and dried over MgSO4. The solvent was removed under vacuum and the crude product purified by column chromatography over silica gel (PetEther/EtOAc) to give 2-butyl-1-benzofuran-3-carbaldehyde (30 g, 74%) as a light brown liquid. The reaction mixture was slowly heated to 60° C. for 72 h cooled to rt poured into ice extracted with EtOAc The organic layer was washed with water, brine dried over MgSO4 The solvent was removed under vacuum the crude product purified by column chromatography over silica gel (PetEther/EtOAc)