Water → HCID 15450533, compound

Participants

Reaction Steps

5-Hydroxybenzo[b]thiophene-3-carboxylic acid (11) (1,140 mg) prepared in above (1) was dissolved in acetic anhydride (2 ml), pyridine (4 ml). After 3 hours, water was added and the mixture was continuously stirred under ice-cooling for 1.5 hours. The deposited crystals were filtered, washed with water and dried to provide 1,349 mg of the title compound (12). Yield: 97.3% mp 239-240° C. 1H NMR δ (CDCl3), 300 MHz; 2.37(H, s), 7.20 (1H, dd, J=2.4 and 8.7 Hz), 7.87 (1H, d, J=8.7 Hz), 8.34 (1H, d, J=2.4 Hz), 8.57 (1H, s);

Provenance & Evidence