Sodium Carbonate → N-Butyloxycarbonyl-3-[3-(2-thiophen-3-yl-imidazol-1-ylmethyl)-phenyl]-5-iso-butylthiophene-2-sulfonamide

Participants

Reaction Steps

To a solution of 3-[3-(2-thiophen-3-yl-imidazol-1-ylmethyl)-phenyl]-5-iso-butyl-N-tert-butylthiophene-2-sulfonamide (38.2 mg, 0.0744 mmol; see step (a)) in CH2Cl2 (1 mL) was added BCl3 (0.2 mL, 1.0 M in hexane) and the reaction mixture was stirred for 1 h at ambient temperature. The reaction mixture was concentrated in vacuo. Water (5 mL) was added to the residue and this was then extracted with EtOAc. The combined organic phase was washed with water and brine, dried (over anhydrous MgSO4) and concentrated in vacuo. To the crude product dissolved in CH2Cl2 (5 mL) was added Na2CO3 (35.5 mg, 0.335 mmol), water (2 mL) and butyl chloroformate (11.4 μL, 0.0893 mmol) and the reaction mixture was stirred for 5 h at ambient temperature. The reaction mixture was diluted with CH2Cl2 (30 mL) and washed with citric acid (10% aq), brine and water, dried (over anhydrous MgSO4), concentrated in vacuo, and the residue purified by flash chromatography using MeOH:CH2Cl2 (5:95) as eluent to give the title compound as a white solid in 67% yield, over two steps, (28 mg, 0.050 mmol).

Provenance & Evidence