Citric Acid → HCID 24954055, compound

Participants

Reaction Conditions

Reaction Steps

Ethanol (42.0 L) was added to reactor at 25-30° C., followed by ethyl 1-ethyl-6-(indan-2-ylamino)-4-oxo-1,8-naphthyridine-3-carboxylate (4.20 kg) with stirring. Aqueous sodium hydroxide solution (prepared by dissolving 3.4 kg of sodium hydroxide into 42.0 L of water) was added to reaction mixture at 25-30° C. and reactor temperature was raised to 50-55° C. The reaction mixture was stirred at 50-55° C. for 2 h and reaction progress was monitored by TLC. After completion of hydrolysis (˜3 h), the reaction mass was, cooled to 25-30° C. and pH was adjusted to 5-6 by addition of citric acid solution (prepared by dissolving 5.2 kg of citric acid in 47.0 L of water). The reaction mass was stirred for 20-25 minutes at 25-30° C. and filtered, the solid mass was washed with water (42.0 L) and acetone (21.0 L). The material was transferred to drying trays and dried with hot-air dryer at 70-75° C. until the water content decreased to 1.0%, yielding the desired compound (90%) as a solid. 1H NMR (DMSO-d6, 500 MHz): 1.40(3H, t, J=7.0 Hz), 2.86-2.90(2H, m), 3.37-3.41(2H, m), 4.38(1H, d, J=5.5 Hz), 4.62 (2H, q, J=7.0 Hz), 7.06(1H, d, J=6.0 Hz), 7.17-7.18(2H, m), 7.26-7.27(2H, m), 7.60(1H, d, J=2.5 Hz), 8.52(1H, d, J=2.0 Hz), 9.00 (1H, s), 15.30(1H, s). 13C NMR (DMSO-d6, 125 MHz): 15.19, 46.92, 52.92, 107.12, 109.42, 121.58, 124.63, 126.41, 140.11, 141.12, 143.33, 143.43, 145.93, 166.12, 177.53.

Provenance & Evidence