Benzyl Chloride → HCID 21517147, compound

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Reaction Steps

2,4,6-tribenzyloxyacetophenone is obtained by the common procedure of reacting 2,4,6-trihydroxyacetophenone with excess benzyl chloride and excess potassium carbonate in dimethylformamide and giving the reaction mixture an aqueous work up. 3-benzyloxy-4-n-propoxybenzaldehyde is similarly prepared from 3-hydroxy-4-n-propoxybenzyl alcohol, excess benzyl chloride and excess potassium carbonate. A warm solution of 2.19 g of the 2,4,6-tribenzyloxyacetophenone and 1.35 g of the benzyloxy-4-n-propoxybenzaldehyde is prepared in 10 ml of absolute ethanol. 15 Milliliters of warm aqueous 60% potassium hydroxide is added all at once. The mixture is stirred and a yellow solid product is formed. 16 Milliliters of absolute ethanol is added and the mixture is added to 300 ml of water and extracted three times with ethyl acetate. The extracts are dried and concentrated to yield 3.2 g of a solid, which is recrystallized to yield 2.6 g (75% yield) of 2,4,6,3'-tetrabenzyloxy-4'-n-propoxychalcone. ##SPC5## 1.38 Grams of this material is dissolved in about 50 ml of ethyl acetate and 200 mg of 5% palladium on charcoal is added. The reaction flask is flushed with hydrogen and then the mixture is stirred under hydrogen at room temperature for about 35 hours. The product is checked by thin layer chromatography and observed to contain essentially a single product. The reaction mixture is filtered and concentrated to yield 0.66 g of a colorless oil, which by NMR is determined to be 2,4,6,3'-tetrahydroxy-4'-n-propoxy dihydrochalcone, ##SPC6##

Provenance & Evidence