1,8-Diazabicyclo(5.4.0)undec-7-ene → 7-bromo-2-(2,4-dimethoxybenzyl)-4-(4-nitrobenzyl)pyrrolo[1,2-a]pyrazin-1(2H)-one

Participants

Reaction Steps

To a solution of EXAMPLE 23C (10 g, 20 mmol in dry dichloromethane (150 mL) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (1.22 g, 8 mmol). The mixture was heated under reflux for 6 hours. After cooling, the reaction mixture was diluted with dichloromethane, and then washed with 0.5 N aqueous HCl (300 mL) and brine. The organic layer was dried over anhydrous Na2SO4, filtered, and concentrated. The residue was purified by flash chromatography (1% methanol in CH2Cl2) to afford the title compound. LC-MS (ESI): m/z 500, 498 (M+H), RT: 2.29 min; 1H NMR (400 MHz, dimethylsulfoxide-d6): δ 3.74 (s, 3H), 3.75 (s, 3H), 4.21 (s, 2H), 4.87 (s, 2H), 6.47 (dd, J=6, 2.4 Hz, 1H), 6.56 (d, J=2.4 Hz, 1H), 6.69 (s, 1H), 6.99 (d, J=1.6 Hz, 1H), 7.06 (d, J=8.4 Hz, 1H), 7.50 (d, J=2.0 Hz, 1H), 7.60 (d, J=8.8 Hz, 2H), 8.20 (d, J=8.4 Hz, 2H).

Provenance & Evidence