Trifluoroacetic acid → 5-(5-chloro-2-fluorophenyl)-3-methyl-3-phenyl-2,3-dihydroisoxazole

Participants

Reaction Steps

To a solution of 5-(5-chloro-2-fluorophenyl)-2-(2,4-dimethoxybenzyl)-3-methyl-3-phenyl-2,3-dihydroisoxazole (2-3, 0.88 g, 1.99 mmol) in anhydrous CH2Cl2 (5 mL) was added trifluoroacetic acid (5 mL) and the resulting purple colored reaction sat for 7 h. 2M Na2CO3 was added until the color changed from purple to peach, and the reaction was immediately extracted with CH2Cl2, dried with MgSO4, filtered and concentrated to provide crude 5-(5-chloro-2-fluorophenyl)-3-methyl-3-phenyl-2,3-dihydroisoxazole (2-4). This crude material was suitable for further transformations. 1H NMR (300 MHz, CDCl3) δ 7.56 (m, 3H), 7.36 (m, 3H), 7.25 (m, 1H), 7.05 (app t, J=9.6 Hz), 6.20 (br s, 1H), 6.03 (d, J=3.4 Hz, 1H), 1.78 (s, 3H). LRMS see table.

Provenance & Evidence