Isobutyl 3-benzyl-5-oxo-2-imidazolidinepropanoate hydrochloride → Isobutyl 5-oxo-2-imidazolidinepropanoate hydrochloride

Beteiligte Stoffe

Reaktionsschritte

To a mixture of 10% palladium on charcoal (1 g) and 99% formic acid (1 ml) in methanol (25 ml), under nitrogen, was added a solution of isobutyl 3-benzyl-5-oxo-2-imidazolidinepropanoate hydrochloride (1 g, 2.93 mmol) and 99% formic acid (1.25 ml) in methanol (25 ml). The mixture was stirred under nitrogen for 6 hours. After addition of water (15 ml) and removal of the catalyst, the solvent was evaporated and the residue was triturated with ethanol to give 0.3 g (41%) of the title compound, m.p. 136°-140° C. The same compound was obtained also by the following procedure: into a mixture of isobutyl 3-benzyl-5-oxo-2-imidazolidinepropanoate hydrochloride (2.2 g, 6.4 mmol), and 10% palladium on charcoal (1.1 g) in water-methanol 2:1 (150 ml) hydrogen was bubbled at room temperature and at atmosphere pressure for 2 hours. Removal of the catalyst and evaporation of the solvent under reduced pressure gave a residue which was triturated with ethanol to afford 14 g (90%) of the title compound, m.p.136°-40° C. NMR (DMSO-d6): deltaH =11.1-9.50 (b.s., 2H, NH2+); 9.20 (b.s., 1H, CONH); 4.95 (t, J=6.2 Hz, 1H, NHCHNH); 3.84 (d, J=6.7 Hz, 2H, COOCH2); 3.65 (s, 2H, NCH2CO); 2.70-2.30 (c.a., 2H, CH2CH2COO); 2.25-1.60 (c.a., 3H, CH2CH2COO, CH(CH3)2); 0.87 (d, J=6.7 Hz, 6H, CH(CH3)2. MS (E.I., 70 eV, 1.5 mA) m/z=214 (M+), 141(M--OC4H9)+, 85 (C3H5N2O)+.

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