Diisopropyl azodicarboxylate → HCID 59497420, compound

Participants

Reaction Conditions

Reaction Steps

3-(2-Oxo-2,3-dihydro-benzoimidazol-1-yl)-hexanoic acid ethyl ester (80 mg, 0.29 mmol), prepared as described above, 4-chloro-3-hydroxymethyl-indole-1-carboxylic acid tert-butyl ester (282 mg, 1 mmol) and triphenylphosphene (223 mg, 0.85 mmol) were combined in a reaction vial and THF (1 mL) was added. The mixture was stirred until complete solution was attained, then cooled to 0° C., and diisopropylazodicarboxylate (0.165 mL, 0.85 mmol) was added dropwise. The reaction mixture was heated in the microwave at 130° C. for 20 minutes, cooled, then diluted with THF (1 mL) and treated directly with the Amberlyst® resin (2.2 g, 2.95 mmol). This reaction mixture was agitated overnight and the resin was then filtered and washed with DMF (2×3 mL) and several portions of methanol. The product was eluted by treating the resin with a 20% solution of formic acid in methanol (2×3 mL) and washing with methanol (3 mL). The combined eluant and final wash was evaporated and redissolved in dichloromethane (1 mL). To this solution was added TFA (0.2 mL) and the reaction mixture was agitated for 1 h. The solvent was evaporated and the residue was purified by preparative HPLC using an acetonitrile/water/formic acid gradient providing the title compound (8 mg, 7%) LCMS (ESMS): m/z 412 (M+H+).

Provenance & Evidence