Yield:-

Reaction Conditions:

with caesium carbonate in N,N-dimethyl-formamide at 25; for 24 h;

Steps:

9

To a solution of 2-benzimidazolepropionic acid (20.5g, 108 mmol) in DMF (200 mL) at 25 ⁰C was added cesium carbonate (52.7 g, 162 mmol) and iodomethane (23.0 g, 162 mmol) and the reaction was stirred vigorously for 24h. The reaction was quenched with water (200 mL) and extracted with ethyl acetate (2 x 20OmL). The combined organics were dried over MgSO₄ and the residue was concentrated. The residue was further azeotroped with toluene (3 x 40OmL) to afford a solid which was used without further purification. To a solution of the resulting solid in TΗF/MeOΗ (1:1, 200 mL) at 25 ⁰C was added potassium hydroxide (5.0 g, 90 mmol) in water (54 mL) and the reaction was stirred for EPO 24h. Concentrated hydrochloric acid (7.4 mL) was then added slowly and the reaction mixture was concentrated. The residue was azeotroped with toluene (3 x 300 mL) to give the titled compound (1-26) as an off-white solid. ESI+ MS: 205 [M+H]⁺.

References:

WO2006/127550,2006,A1 Location in patent:Page/Page column 38-39