Benzenesulfonic Acid → (5-methoxy-3-methyl-1-oxo-3,4-dihydro-1H-naphthalen-2-ylidene)-acetic acid ethyl ester

Participants

Reaction Steps

In a heavy walled sealed tube, 5-methoxy-3-methyl-3,4-dihydro-2H-naphthalen-1-one (1.3 g, 6.8 mmol), ethyl glyoxylate (3 mL, 50% solution in toluene), benzenesulfonic acid (100 mg), magnesium sulfate (5 g), and toluene (30 mL) were heated to 120° C. for 13 hours. The reaction was cooled to room temp, filtered, diluted with water, and extracted with ethyl acetate. The extracts were washed with brine, dried with sodium sulfate, and concentrated. The crude residue was purified by flash column chromatography to yield the desired product (960 mg, 51% yield). LCMS-ESI+ (m/z): [M+H]+ calcd for C16H19O4: 275.13. Found: 275.26.

Provenance & Evidence