反应详情

The 2-(2-(3-(2,6-dimethylbenzyloxy)phenyl)-2-oxoethyl)malonic acid (4.8 g) was suspended in toluene (20 ml), and the mixture was heated to reflux for 7 hours. The mixture was allowed to cool to room temperature overnight. The desired product crystallized out, and the suspension was stored at 5° C. for 4 hours. The solid was collected by filtration and dried under vacuum to give 2.2 grams of 4-[3-(2,6-dimethylbenzyloxy)-phenyl]-4-oxobutanoic acid. The mother liquor was evaporated and the residue was triturated with saturated sodium bicarbonate solution (2×50 ml). The aqueous solution was filtered, and the filtrate was acidified with hydrochloric acid to pH 1. The resulting suspension was extracted with ethyl acetate (100 ml), and the organic layer was washed with brine. The ethyl acetate extract was dried over sodium sulfate, filtered, and evaporated under vacuum to give an additional 0.4 grams of the desired product. Total of 2.6 g (69% yield). NMR (CDCl3, δ) 7.59-7.65 (m, 2H), 7.40 (t, 1H), 7.15-7.23 (m 2H), 7.06-7.10 (2s, 2H), 5.09 (s, 2H), 3.32 (t, 2H), 2.82 (t, 2H), 2.39 (s, 6H). HPLC: DPA-9.02 minutes.

1. temperaturethe mixture was heated
2. temperatureto reflux for 7 hours
3. customThe desired product crystallized out
4. filtrationThe solid was collected by filtration
5. customdried under vacuum