反应详情

2-(4-isobutylphenyl)-N-hydroxy-propionamidine (0.097 g, 0.44 mmol) is dissolved in acetic acid (3 mL) and treated at r.t. with acetic anhydride (0.06 mL, 0.66 mmol). 10% Pd on activated charcoal (0.03 g) is added and H2 is bubbled into the flask until the complete disappearance of the starting reagent. Methyl alcohol (5 mL) is added, the catalyst filtered off on a Celite cake and the solvents evaporated under reduced pressure to give an oily residue. Crystallisation of the crude residue from n-hexane gives 2-(4-isobutylphenyl)propionamidine acetate salt as white solid (0.106 g, 0.4 mmol). Yield 91%. m.p. >220° C. 1H-NMR (DMSO-d6): δ 8.70-8.50 (bs, NH3++NH); 7.42 (d, 2H, J=7 Hz); 7.23 (d, 2H, J=7 Hz); 3.85 (q, 1H, J=8 Hz); 2.52 (d, 2H, J=8 Hz); 1.97 (m, 1H); 1.75 (s, 3H); 1.60 (d, 3H, J=8 Hz); 0.95 (d, 6H, J=8 Hz).

1. customH2 is bubbled into the flask until the complete disappearance of the starting reagent
2. additionMethyl alcohol (5 mL) is added
3. filtrationthe catalyst filtered off on a Celite cake
4. customthe solvents evaporated under reduced pressure
5. customto give an oily residue
6. customCrystallisation of the crude residue from n-hexane