Oxygen → HCID 15541468, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 22 (0.60 g, 1.6 mmol) in acetic acid (15 mL) was added Pd on carbon (10%, 300 mg) and ammonium formate (4.3 g, 55.8 mmol) (caution: in a large scale reaction exothermicity may be a problem; rigorous exclusion of oxygen is desirable) and heated at 120° C. for 20 h. Catalyst was filtered through a bed of Celite® and acetic acid was evaporated under reduced pressure. Water (50 mL) was added to the residue and solid separated was filtered. Pure Z-isomer was isolated by preparative HPLC using Intersil ODS-3 preparative column (250×4.6 mm, 5 μm) running at a rate of 15 mL per minute using methanol:acetonitrile:water (3:3:2) containing formic acid (0.05%): mp 65-66° C.; 1H NMR (400 MHz, DMSO-d6) δ 12.05 (br s, 1H), 7.48 (d, J=9.2 Hz, 2H), 7.29 (d, J=8.4 Hz, 2H), 7.13 (s, 1H), 7.03 (overlapped d, J=8.8 Hz, 2H), 7.01 (overlapped d, J=8.4 Hz, 2H), 6.56 (d, J=2.0 Hz, 2H), 6.49 (t, J=2.0 Hz, 1H), 4.90 (dd, J=9.2 and 4.4 Hz, 1H), 3.77 (s, 3H), 3.75 (s, 6H), 3.38 (dd, J=14.8 and 4.8 Hz, 1H) and 3.13 (dd, J=14.4 and 9.2 Hz, 1H); MS (EI) m/z 300[M]+.

Provenance & Evidence