Sodium Carbonate → N-Butyloxycarbonyl-3-[3-(2-benzoimidazol-1-ylacetyl)phenyl]-5-iso-butyl-thiophene-2-sulfonamide

Participants

Reaction Steps

To a solution of 3-[3-(2-Benzoimidazol-1-ylacetyl)phenyl]-5-iso-butyl-N-tert-butylthiophene-2-sulfonamide (67.3 mg, 0.151 mmol; see step (b)) in CH2Cl2 (1 mL) was added BCl3 (0.3 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. CH2Cl2 (30 mL) was added to the residue and this was washed with water. The organic phase was dried (over anhydrous MgSO4), concentrated in vacuo. To the crude product dissolved in CH2Cl2 (5 mL) was added Na2CO3 (72 mg, 0.680 mmol), water (2 mL) and butyl chloroformate (24.9 μL, 0.196 mmol), and the reaction mixture was stirred for 2 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 (6:94) as eluent to give the title compound in 90% yield, over two steps, (66.2 mg, 0.135 mmol).

Provenance & Evidence