2,2,2-Trifluoroethyl trifluoromethanesulfonate → HCID 70148942, compound

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Reaction Steps

Add to a suspension of sodium hydrdide (0.029 g, 1.21 mmol) in anhydrous dimethylformamide (5 mL) a suspension of 1-(t-butoxycarbonyl)-4-(1H-benzimidazol-2-yl)[1,4]diazepan (0.38 g, 1.2 mmol, Preparation 9) in anhydrous dimethylformamide (7 mL). Stir for 3 hours at room temperature and add a large excess of 1,1,1-trifluoro-methanesulfonic acid 2,2,2-trifluoro-ethyl ester. Stir overnight at room temperature, quench the reaction with water, wash the organic phase with water, dry (MgSO4), filter and concentrate in vacuo to afford 4-[1-(2,2,2-trifluoro-ethyl)-1H-benzoimidazol-2-yl]-[1,4]diazepane-1-carboxylic acid tert-butyl ester. Repeat this preparation using 2.88 mmol of 1-(t-butoxycarbonyl)-4-(1H-benzimidazol-2-yl)[1,4]diazepan. Combine the product from both reactions and purify by column chromatography on silica gel eluting with 30% ethyl acetate in hexane and concentrate the appropriate fractions to afford 0.48 g of 4-[1-(2,2,2-trifluoro-ethyl)-1H-benzoimidazol-2-yl]-[1,4]diazepane-1-carboxylic acid tert-butyl ester.

Provenance & Evidence