Acetic Anhydride → 6-Chloro-4-hydroxy-1-methylquinolin-2(1H)-one

Participants

Reaction Steps

5-Chloro-N-methyl anthranilic acid (15g; 0.081 mole) was dissolved in acetic acetic acid (41 ml) and acetic anhydride (41 ml) and the dark mixture refluxed for 12 hours. After cooling the red solution was poured onto crushed ice, basified with 2.5N sodium hydroxide solution and filtered free of tar. The filtrate on acidification to pH5 gave the carbostyril as a yellow solid, m.p. (AcOH) 317°-318°C (Found; C, 57.39; H, 3.98;N, 6.83; Cl, 16.69; C10H8NClO 2 requires C, 57.29; H, 3.85; N, 6.68; Cl, 16.91%).

Provenance & Evidence