2,2-dimethyl-3H-1-benzofuran-5-carbaldehyde

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

Procedure: To a solution of 2,3-dihydro-2,2-dimethylbenzofuran-5-carboxaldehyde 14 (250 mg, 1.42 mmol) in MeOH (10 mL) was added aniline (0.14 mL, 1.022 mmol), NaCNBH3 (178 mg, 2.84 mmol) and ZnCl2 (dried in oven) (387 mg, 2.84 mmol). The reaction was stirred at room temperature overnight, and then the solvent was removed by rotary evaporation. 0.1M NaOH was added to the resulting residue, which was extracted with EtOAc (×2). The combined organic layers were dried over MgSO4 and concentrated in vacuum to give 301 mg of the product (84%). 1H NMR (CDCl3): d 7.29-7.22 (m, 3H), 7.17 (d, J=8.0 Hz, 1H), 6.95-6.70 (m, 4H), 4.28 (s, 2H), 3.06 (s, 2H), 1.55 ppm (s, 6H). the solvent was removed by rotary evaporation 0.1M NaOH was added to the resulting residue, which was extracted with EtOAc (×2) The combined organic layers were dried over MgSO4 concentrated in vacuum