Isobutyl 4-oxobutanoate → 2,5-Dioxo-1-ethylhexahydro-1H-pyrrolo[1,2-a]imidazole

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Reaction Steps

Glycine ethylamide hydrochloride (2.1 g, 15.1 mmol) and isobutyl 4-oxobutanoate (2 g, 12.6 mmol) were reacted together according the procedure of Example 2 to give the title compound, 0.5 g (23.5%) as a viscous oil. Rf=0.51 (silica gel plates, eluent dichloromethane-methanol 9:1). NMR (CDCl3): deltaH =5.27 t, J=6 Hz, 1H, N--CH--N); 4.20 and 3.45 (ABq, J=17 Hz, 2H, N--CH2 --CO); 3.25 (q, J=7 Hz, 2H, NCH2CH3); 2.70-1.75 (c.a., 4H, COCH2CH2CH); 1.12 (t, J=7 Hz, 3H, CH3). MS (E.I., 70 eV, 1.5 mA) m/z=168 (M+), 112 M--C3H4O)+, 97 (M--C4H7O)+.

Provenance & Evidence