Bromine → 6-Bromo-7-(1,1-dimethylethyl)-2-(trifluoromethyl)-2h-1-benzopyran-3-carboxylic acid

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Reaction Steps

7-(1,1-Dimethylethyl-2-(trifluoromethyl)-2H-1-benzopyran-3-carboxylic acid (Example 12) (0.6 g, 2 mmol), chloroform (50 mL), iron filings (0.01 g, 0.2 mmol), and bromine (0.48 g, 3.00 mmol) were stirred at reflux for 16 h. The mixture was allowed to cool and was washed with brine (2×50 mL). After drying over MgSO4, the mixture was filtered, concentrated in vacuo, and the residue crystallized from ether-hexanes yielding the title compound as a white solid (0.5 g, 66%): mp 198.6-199.9° C. 1H NMR (acetone-d6/300 MHz) 7.85 (s, 1H), 7.72 (s, 1H), 7.13 (s, 1H), 5.83 (q, 1H, J=7.2 Hz), 1.5 (s, 9H). Anal. Calc'd for C15H14O3F3Br: C, 47.52; H, 3.72; N, 21.07. Found: C, 47.42; H, 3.68; N, 21.15.

Provenance & Evidence