Selenium Dioxide → 7-Butyramido-2-formylquinoline-5,8-dione

Participants

Reaction Steps

In a 25 ml. round-bottomed flask equipped with a magnetic bar, water-cooled reflux condenser, and an argon filled balloon, 7-butyramido-2-methylquinoline-5,8-dione (30) (prepared as described in Example 30) (0.516 g., 2 mmol), selenium dioxide (0.255 g., 2.3 mmol), 12 ml. of dried, distilled 1,4-dioxane, and 0.25 ml. of water were stirred and slowly heated to reflux over a two-hour period. The reaction was monitored by TLC and found to be complete after 33.5 hours. The selenium metal was allowed to settle, and the supernatant solution was pipetted off and filtered. 1,4-Dioxane (10 ml.) was added to the residue, stirred and refluxed for five minutes. The entire mixture was filtered and the selenium was washed with dichloromethane (10 ml.). All filtrates were combined and stored at 4EC overnight. This solution was diluted with 50 ml of dichloromethane and washed with a 3% sodium bicarbonate solution (2×50 ml.). The organic layer was dried with magnesium sulfate and rotoevaporated to give a pale yellow product. The solid was dried under vacuum overnight and weighed 0.356 g. (yield of 65%). The product was recrystallized from ethyl acetate: mp. 208-210E C; 1H NMR (CDCl3) * 1.02 (3H, t, J=7.4 Hz, C-7NHCOCH2CH2CH3),1.70 -1.89 (2H, m, 7NHCOCH2CH2CH3), 2.52 (2H, t, J=7.4 Hz, 7NHCOCH2CH2CH3), 8.06 (1 H, s, C-6H), 8.31 (1 H, d, J=8.0 Hz, C-3H), 8.39 (1H, br. s, C-7NH), 8.61 (1H, d, J=8.0 Hz, C4H), 10.28 (1H, s, C-2CHO); IR (KBr) vmax 3299, 3081, 2966, 2935, 2876, 1723, 1694, 1638, 1606, 1505 cm-1 ; EIMS, m/e (relative intensity) 272 (54), 202 (36), 175 (9); HRMS, m/e for C14H12N2O4 calculated 272.079707, found 272.078696; analysis for C14H12N2O4 calculated C, 61.76; H, 4.44; N, 10.29; found C, 61.31; H, 4.36; N, 9.94.

Provenance & Evidence