Triethylamine → HCID 66835866, compound

Participants

Reaction Steps

A round bottom flask charged with molecular sieves, 4A (189 mg, 1.918 mmol) was flame-dried, then allowed to cool to room temperature. To this vial were added 4-bromo-1H-benzo[d]imidazole (0.378 g, 1.918 mmol), copper (II) acetate (0.523 g, 2.88 mmol), and 4-fluorophenylboronic acid (0.805 g, 5.76 mmol) followed by CH2Cl2 (Volume: 9.59 ml) and triethylamine (0.695 ml, 4.99 mmol). The heterogeneous green reaction was stirred at room temperature. After 19 h, the reaction mixture was filtered through a disposable filter funnel and the filter cake rinsed with CH2Cl2. The filtrate was concentrated to afford a green residue. The crude material was dissolved in a minimal amount of CH2Cl2 to be chromatographed. Purification of the crude material by silica gel chromatography using an ISCO machine (24 g column, 35 mL/min, 0-100% EtOAc in hexanes over 25 min, tr=13 min) gave 4-bromo-1-(4-fluorophenyl)-1H-benzo[d]imidazole (158 mg, 0.299 mmol, 15.56% yield) as a white solid. LC-MS showed by-product was present. The material was re-dissolved in a minimal amount of CH2Cl2 (required a few drops of MeOH). Purification of the crude material by silica gel chromatography using an ISCO machine (12 g column, 30 mL/min, 0-25% EtOAc in hexanes over 13 min, tr=10 min) gave Preparation 47A (158 mg, 0.299 mmol, 15.56% yield) as a white solid. LC-MS showed the product was 55% pure. The mixture was further purified by MPLC (40 g column, 36 mL/min, 30-60% EtOAc in hexanes) to afford Preparation 47A as a white solid (51 mg, 9.1%). MS (ESI): m/z=291.0 [M+H]+. HPLC Peak tr=1.70 minutes was product. HPLC conditions: Column:Luna C18 4.6×30 mm 3u A:10:90 H2O:ACN NH4OAc/B:10:90 H2O:ACN NH4OAc; 0%-95% B in 2 min; 4 mL/min flow.

Provenance & Evidence