Sodium Carbonate → Telmisartan Impurity 13

Participants

Reaction Conditions

Reaction Steps

To a solution of 6-bromo-2,4-dimethyl-1H-benzimidazole (200 mg, 0.90 mmol) in degassed dioxane (2 mL) was added ((trans-bis(acetato)bis[o-(di-o-tolylphosphino)benzyl]dipalladium(II))) (30 mg, 0.05 mmol), molybdenum hexacarbonyl (120 mg, 0.45 mmol) and a solution of Na2CO3 (283 mg, 2.67 mmol) in degassed water (2.4 ml). The mixture was stirred for 20 seconds and then heated at 165° C. for 15 minutes in a microwave reactor with absorption set at very high for 20 minutes. The reaction vessel was vented and filtered through diatomaceous earth. The solution was extracted with EtOAc and the aqueous phase was back extracted with additional EtOAc (2×). The combined organic extracts were set aside. Water (5 mL) was added to the aqueous extract which was then acidified with 0.5 M HCl to pH 3. The resulting solids were air dried to provide the title compound (97 mg, 57%).

Provenance & Evidence