反应详情

1-[2-Methyl-5-(ethyloxy)-4-nitrophenyl]-4-[2-(methylsulfonyl)ethyl]piperazine (9.7 g, 26 mmol) was taken up in EtOH (100 mL). The catalyst, 5% sulfided platinum on carbon (1.0 g) was added. The reaction was placed under 1 atm of H2 gas and was allowed to stir at rt overnight. The catalyst was filtered off and the filtrate was concentrated onto silica in vacuo. The product was purified on a 120 g ISCO column (DCM to 2% (2N NH3 in MeOH) to give the title compound of Step B (1.9 g, 5.7 mmol, 22%) as a pale orange oil. The mixed fractions (product and starting material) were resubmitted to the above conditions to provide additional product (5.2 g, 15 mmol, 58%). 1H NMR (400 MHz, CDCl3) δ 6.53 (s, 1H), 6.52 (s, 1H), 3.99 (q, J=7.0 Hz, 2H), 3.56 (s, 2H), 3.15 (t, J=6.3 Hz, 2H), 3.05 (s, 3H), 2.91 (t, J=6.4 Hz, 2H), 2.84-2.78 (m, 4H), 2.67-2.54 (m, 4H), 2.13 (s, 3H), 1.38 (t, J=7.0 Hz, 3H).

1. filtrationThe catalyst was filtered off
2. concentrationthe filtrate was concentrated onto silica in vacuo
3. customThe product was purified on a 120 g ISCO column (DCM to 2% (2N NH3 in MeOH)