Acetic Acid → Ethyl 2-{(E)-2-[3-(difluoromethoxy)-2-hydroxyphenyl]vinyl}imidazo[1,2-a]pyridine-3-carboxylate

Participants

Reaction Steps

The Step 1 intermediate (4.3 g, 9.674 mmol) was treated with 48% hydrobromic acid (20 mL) in glacial AcOH (20 mL) as described in Intermediate 6 gave 3.1 g of the product as white solid; 1H NMR (300 MHz, DMSO-d6) δ 1.44 (t, J=7.2 Hz, 3H), 4.44 (q, J=7.2 Hz, 2H), 6.92 (d, J=7.8 Hz, 1H), 7.12 (t, J=74.1 Hz, 1H), 7.15-7.22 (m, 2H), 7.48 (d, J=7.8 Hz, 1H), 7.57 (t, J=7.8 Hz, 1H), 7.75 (d, J=9.3 Hz, 1H), 7.95 (d, J=16.2 Hz, 1H), 8.08 (d, J=15.9 Hz, 1H), 9.24 (d, J=6.9 Hz, 1H), 9.83 (br, 1H); APCI-MS (m/z) 375.16 (MH)+.

Provenance & Evidence