Benzyl chloroformate → N-(4-{[(Benzyloxy)carbonyl]amino}-3-methylbenzoyl)serine methyl ester

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Reaction Steps

10% Pd/C (1.2 g) was added to N-(3-methyl-4-nitrobenzoyl)serine methyl ester obtained in Example (109a) (2.39 g, 8.47 mmol) in ethanol (20 mL), and the mixture was stirred in a hydrogen atmosphere at room temperature for one hour. Pd/C was filtered off, and the filtrate was concentrated under reduced pressure. Water (10 mL), THF (10 mL), sodium bicarbonate (0.84 g, 10 mmol) and benzyl chloroformate (1.62 g, 9 mmol) were added to the resulting residue, and the mixture was stirred at room temperature for one hour. Following extraction with ethyl acetate, the organic layer was washed with water, a 1 N aqueous hydrochloric acid solution and brine, dried over magnesium sulfate, and concentrated. Thereafter, the resulting residue was purified by silica gel column chromatography (elution solvent: chloroform/methanol=1/0, 98/2, 96/4, 94/6, 92/8) to obtain 1.8 g of the title compound as a colorless solid (55%).

Provenance & Evidence