ethyl 3-[N,N'-bis(benzyloxycarbonyl)hydrazino]-2,5-dioxopyrrolidine-3-carboxylate → Ethyl 3-amino-2,5-dioxopyrrolidine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of the compound of Example 1 (496 mg) in acetic acid (15 ml) was added platinum oxide (102 mg). This mixture was stirred vigorously at 50° C. under hydrogen (atmospheric pressure) for 6 hours. During this reaction, to remove carbon dioxide generated with the progress of the reaction, the gas in the reactor was replaced with hydrogen gas several times. The reaction mixture was filtered through a Celite pad and then the Celite was washed with a small amount of acetic acid. The filtrate combined with the washers was concentrated and to the resulting residue was added toluene to remove azeotropically the residual acetic acid and then the mixture was concentrated again. To the residue was added ethyl acetate and the insoluble material was filtered off, and then the ethyl acetate solution was concentrated to give a crude product which was then purified by a flash column chromatography (chloroform:methanol=30:1) to give the desired product (126 mg, 64%) as crystal. 1H NMR (CDCl3) data of this product were consistent with those of an optical active substance described in J. Med. Chem., 1998, 41, p. 4118 to 4129.

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