Water → HCID 15680102, compound

Participants

Reaction Steps

Part A. A solution of 2-mercapto-1H-benzimidazole (4.75 g, 31.6 mmol), ethyl 5-bromovalerate (5.00 mL, 31.6 mmol), potassium carbonate (5.68 g, 41.1 mmol), and tetra-n-butylammonium iodide (2.33 g, 6.31 mmol) in tetrahydrofuran (200 mL) was heated to reflux for 24 hours. The solution was cooled, and poured into water (200 mL). The layers were separated, and the aqueous layer was extracted with methylene chloride (2×200 mL). All three organic phases were washed over brine, combined, dried over anhydrous magnesium sulfate, filtered and evaporated to afford a pale yellow oil. The oil was purified by elution through a short plug of silica gel (1:1 ethyl acetate-hexane) to afford the product, 2-[4-(carboethoxy)butylthio]-1H-benzimidazole, as a waxy solid, m.p. 88°-90° C. (8.03 g, 28.9 mmol, 91%). 1H NMR (CDCl3): 10.61 (1H, br s); 7.66 (1H, br s); 7.36 (1H, br s); 7.19 (2H, dd, J=5.7, 2.7 Hz); 4.12 (2H, q, J=7.0 Hz); 3.30 (2H, t, J=6.2 Hz); 2.32 (2H, t, J=5.9 Hz); 1.95-1.74 (4H, m); 1.24 (3H, t, J=7.0 Hz).

Provenance & Evidence