Methanol → HCID 15718093, compound

Participants

Reaction Steps

A mixture of 6-hydroxy-9-oxo-9H-xanthene-2-carboxylic acid (Gapinski, D. M. "Leukotriene Antagonists", U.S. Pat. No. 4,996,230, which is incorporated herein by reference, 1991; 10.6 g, 41.4 mmol) and concentrated sulfuric acid (1 mL) in methanol (100 mL) was refluxed for 48 hours. The mixture was cooled to room temperature and the resulting precipitate collected by vacuum filtration. The filtrate was concentrated in vacuo and diluted with water, which resulted in additional precipitate. This was collected and combined with the first fraction to provide 10.8 g (97%) of the title product: 1H-NMR (DMSO-d6) 11.03 (s, 1H, --OH), 8.56 (d, J=2 Hz, 1H), 8.18 (dd, J=9, 2 Hz, 1H), 7.96 (d, J=9 Hz, 1H), 7.59 (d, J=9 Hz, 1H), 6.88 (dd, J=9, 2 Hz, 1H), 6.81 (d, J=2 Hz, 1H), 3.86 (s, 3H); MS-FAB (m/e) 271 (p+1, 6); IR (KBr, cm-1) 3093 (b), 1727, 1604, 1459, 1282, 1120, 767. Anal. (C15H10O5 :

Provenance & Evidence