Hydrochloric Acid → HCID 4769382, compound

Participants

Reaction Steps

To a solution of sodium hydroxide (0.77 g, 19.3 mmol) in water (46.5 mL), was added N-acetyl-5-iodoisatine (107) (2.50 g, 7.86 mmol) (Aeschlimann, J. A. The relative stability of the quinolone and indolinone rings. J. Chem. Soc. 1926, 2908). The mixture was refluxed for 3 h. After cooling to room temperature and then 0° C., a 6 N aqueous hydrochloric acid solution was added (pH=1). The precipitate was filtered and suspended in a saturated aqueous sodium bicarbonate solution (10 mL). The remaining precipitate was filtered and the filtrate was extracted with dichloromethane (6×50 mL). The aqueous layer was acidified up to pH=1 with a 6 N aqueous hydrochloric acid solution and left 1 h at 0° C. The precipitate formed was filtered and dried under vacuum at 35° C. to give compound 108 (0.90 g, 2.86 mmol) as an ocher solid. Yield 36%; mp 361-363° C.; IR (KBr) ν 1219, 1636, 1701, 2800-3150, 3200-3500 cm−1; 1H NMR (200 MHz, DMSO-d6) δ 6.92 (s, 1H), 7.18 (d, 1H, J=8.7 Hz), 7.84 (dd, 1H, J=1.8, 8.7 Hz), 8.57 (d, 1H, J=1.8 Hz), 12.17 (s, 1H), 14.00 (m, 1H); ESI-MS m/z 313.7 [M−H].

Provenance & Evidence