Diethyl Ether → HCID 71738666, compound

Participants

Reaction Steps

To the stirred solution of o-nitrohydrocinnamaldehyde 4a-e (6 mmol) and PhNO (6 mmol) in DMSO (20 mL), L-proline (20 mol %) was added at 25° C. and allowed to stir for 20 min. After completion of reaction, as indicated by the change in color from green to yellow, large excess (200 mL) of diethyl ether was poured into the reaction mixture and stirred for additional 10 min. The combined organic mixture was washed with H2O (5×20 mL). The organic layer was separated and aqueous layer was extracted with diethyl ether (2×50 mL). Combined organic layers were washed with brine (5×50 mL), dried over anhydrous Na2SO4 and concentrated under reduced pressure to give the crude product. The crude α-aminooxylated aldehyde was dissolved in MeOH (20 mL) and to this mixture 10% Pd/C (5 wt %) was added. The reaction mixture was then stirred at 25° C. for additional 6 h. After the completion of reaction (monitored by TLC), it was filtered through celite (MeOH eluent) and the solvent evaporated under reduced pressure. Chromatographic purification of the crude product [flash silica gel (230-400 mesh) and petroleum ether:EtOAc:Et3N (60:38:2)] gave the pure (R)-tetrahydroquinolin-3-ol derivatives to 5a-e.

Provenance & Evidence