Diisopropylethylamine → 1-(2-Aminoethyl)-3-[(5-chlorothien-2-yl)sulfonyl]-1,3-dihydro-2H-benzimidazol-2-one

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Reaction Steps

A solution of [2-(2-oxo-2,3-dihydrobenzimidazol-1-yl)ethyl]carbamic acid t-butyl ester (27 mg, 0.1 mmol) in THF at room temperature is treated with (5-chlorothien-2-yl)sulfonyl chloride (26 mg, 0.12 mmol) followed by diisopropylethylamine (25 uL, 0.2 mmol) and 4-dimethylaminopyridine (5 mg), stirred at room temperature for 16 h and concentrated in vacuo. The resultant residue is dissolved in THF, treated with HCl in dioxane (4 N) (1 mL), stirred for 4 h and concentrated in vacuo. This residue is dissolved in a mixture of DMSO, methanol and water and purified by Gilson1 preparative HPLC to give the title product, 10 mg, [M+H] 358, retention time (RT) 2.18 minutes. 1Gilson Preparative HPLC conditions: Gilson Preparative HPLC system; YMC Pro C18, 20 mm×50 mm ID, 5 uM column; 2 mL injection; Solvent A: 0.02% TFA/water; Solvent B:0.02% TFA/acetonitrile; Gradient: Time 0: 95% A; 2 min: 95% A; 14 min: 10% A, 15 min: 10% A, 16 min: 95% A; Flow rate 22.5 mL/min; Detection: 254 nm DAD.

Provenance & Evidence