Diethyl Ether → HCID 395516, compound

Participants

Reaction Steps

To a solution the monotetrahydropyranyl ether of the dihydroxydeoxybenzoin (6.87 g, 22 mmole) and 4-hydroxybenzaldehyde (2.44 gm, 20 mmole) in dry benzene (100 ml) was added dry piperidine (0.12 ml). It was refluxed for 30 hours removing water azeotropically adding fresh portions of dry benzene from time to time to replenish the distilled benzene. The reaction mixture was cooled and washed with water (2×40 ml). The organic layer was dried (Na2SO4) and concentrated. The residue left was allowed to stand for 24 hours. The solidified material was filtered off and washed with chloroform to afford the dihydrobenzopyranone. The filtrate was collected, concentrated and residue chromatographed over a silica gel column eluting rapidly with 2% ethyl acetate in hexane, to afford, first, the unreacted THP ether of deoxybenzoin (starting compound). With increasing polarity (20% ethyl acetate in hexane), the 2-phenylchalcone (desired compound) was obtained which was crystallised from benzene-hexane, m.p. 140° C. (6 g, 72.1%).

Provenance & Evidence