Sodium Bicarbonate → 2,3-Dimethoxy-6-(5-nitroisoquinolin-4-yl)phenol

Participants

Reaction Steps

After dissolving isoquinoline 4a (5.285 g, 0.014 mol) in 200 ml of methanol by gentle heating, p-toluenesulfonic acid monohydrate (8.15 g; 0.043 mol) was added in several portions. Stirring was continued for four hours at room temperature. After completion of the reaction, the solution was made basic by adding saturated sodium bicarbonate. The product was then extracted with dichlormethane (3×250 ml), dried (Na2SO4), and concentrated. The resulting yellow solid (4.65 g; 98%) was used directly in the next reaction. An analytical sample was recrystallized from methanol: mp 170-174° C.; 1H NMR: (300 MHz, CDCl3): 9.33 (s, 1H); 8.62 (s, 1H); 8.24 (dd, 1H, J=7.2, 0.9 Hz); 7.99 (dd, 1H, J=6.3, 1.2 Hz); 7.67 (t, 1H, J=7.8 Hz); 6.96 (d, 1H, J=8.7 Hz); 6.59 (d, 1H, J=8.7 Hz); 5.88 (bs, 1H); 3.94 (s, 3H); 3.92 (s, 3H). CIMS m/z: 327 (M+H+, 100%). Anal Calc'd for C17H14N2O5: C, 62.57; H, 4.32; N, 8.58. Found: C, 62.18; H, 4.38; N, 8.35.

Provenance & Evidence