Hydrogen Bromide → 4.7-Dihydroxy-8-methyl-3-(3-fluorophenylcarbamoyl)coumarin

Participants

Reaction Conditions

Reaction Steps

To a solution of the compound of Step A (471 mg, 1.12 mmol) in acetic acid (10 ml) was added hydrobromic acid (48%, 5 ml). The mixture was refluxed at 100° C. for 18 hours. After cooling to room temperature, the reaction mixture was poured into water and a precipitate formed. After filtration, the solid was washed with water and then crystallized from dioxane-methanol. The title product was obtained as a white crystalline solid, mp 287°-289° C., (94.9 mg, 0.307 mmol, yield 27.4%). Analysis: Calculated for C17H12NO5F: C, 62.01 ; H, 3.65; N, 4.26. Found: C, 6204; H, 3.65; N, 4.34. 1H NMR (DMSO-d6): 7.74 (d, J=8.70 Hz, 1H), 7.65 (d, J=11.3 Hz, 1H), 7.43 (m, 1H), 7.40 (m, 1H), 7.04 (m, 1H), 6.98 (d, J=8.70 Hz, 1H), 2.26 (s, 3H).

Provenance & Evidence