1-Ethyl-3-(3'-dimethylaminopropyl)carbodiimide → Ethyl trans(+/-)-2-[(5-{[(4-chloro-5-ethyl-1H-imidazol-2-yl)carbonyl]amino}-1,3-dihydro-2H-isoindol-2-yl)carbonyl]cyclopropanecarboxylate

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Reaction Steps

tert-Butyl 5-{[(4-chloro-5-ethyl-1H-imidazol-2-yl)carbonyl]amino}-1,3-dihydro-2H-isoindole-2-carboxylate (described in Example (92a), 0.17 g, 0.42 mmol) was dissolved in dichloromethane (3 mL) and methanol (1 mL). A 4 N hydrochloric acid/ethyl acetate solution (15 ml, 60 mmol) was added, followed by stirring for 20 minutes. The solvent was evaporated under reduced pressure. The resulting residue was dissolved in dichloromethane (5 mL) and DMA (5 mL). trans-2-(Ethoxycarbonyl)cyclopropanecarboxylic acid (described in Wessjohann, Ludger A.; Fulhorst, Michael; Zakharova, Svetlana, Pol. J. Chem., 80, 4, 2006, 673-678, 87 mg, 0.55 mmol), WSC (191 mg, 1 mmol) and DMAP (10 mg) were added, and the mixture was stirred at room temperature for one hour. The reaction solution was concentrated, diluted with ethyl acetate, washed with water and brine, and dried over anhydrous magnesium sulfate. Following concentration under reduced pressure, the residue was purified by silica gel column chromatography (elution solvent: chloroform/methanol=95/5, 90/10) to obtain 117 mg of the title compound as a light brown solid (65%).

Provenance & Evidence