4-Methylmorpholine → 8-Fluoro-4-(2-hydroxyethyl)-3-oxo-3,4-dihydro-2H-quinoxaline-1-carboxylic acid 2-methyl-4-(2,3,4,5-tetrahydrobenzo[b]azepine-1-carbonyl)benzylamide

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Reaction Steps

To a solution of {5-fluoro-4-[2-methyl-4-(2,3,4,5-tetrahydrobenzo[b]azepine-1-carbonyl)benzylcarbamoyl]-2-oxo-3,4-dihydro-2H-quinoxalin-1-yl}acetic acid from Example 8 (70 mg, 0.13 mmol) in THF (4.0 ml) was added N-methylmorpholine (18 μl, 0.18 mmol. The solution was cooled in an ice/water bath and isobutyl chloroformate (23 μl, 0.18 mmol) was added. The mixture was stirred in the ice/water bath for 1 h, filtered and added to a solution of sodium borohydride (12 mg, 0.32 mmol) in water (1.0 ml) in an ice/water bath. The mixture was allowed to warm to room temperature slowly and stirred at room temperature for 1 h. Saturated ammonium chloride (1 ml) was added and the mixture was evaporated in vacuo. The residue was taken up in water and extracted with chloroform. The organic phase was washed with brine, dried and evaporated in vacuo to give a white solid; yield 56 mg, 81%.

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