1,1'-Carbonyldiimidazole → (r)-Tert-butyl 2-(5-(4-carbamoyl-1h-benzimidazol-2-yl)thiophen-2-yl)pyrrolidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of EXAMPLE 16B (2.4 g) in pyridine (20 mL) and DMF (20 mL) was added CDI (1.6 g), and the mixture was stirred at 40° C. for 1 hour. 2,3-Diaminobenzamide dihydrochloride (1.8 g) was added, and the mixture stirred at ambient temperature overnight and concentrated. The concentrate was stirred in of acetic acid (20 mL) at 80° C. for 4 hours and concentrated. The concentrate was partitioned between ethyl acetate and saturated sodium bicarbonate solution, and the extract was washed with water and concentrated. The concentrate was purified by flash chromatography on silica gel with 40-80% ethyl acetate in hexane.

Provenance & Evidence