Quinoline → (Z)-Ethyl cinnamate

Participants

Reaction Steps

Ethyl phenylpropiolate (10.8 g, 0.062 mol) was dissolved in hexane (540 ml), followed by addition of quinoline (11.2 g) and palladium on calcium carbonate (Lindlax catalyst, 3.6 g). The resulting reaction mixture was stirred under hydrogen (1 atm) at room temperature, and the progress of the reaction was monitored closely by GC analysis. The reaction was stopped by displacement of the hydrogen atmosphere with nitrogen once the rate of absorption of hydrogen was observed to decrease abruptly. The resulting mixture was filtered through a pad of diatomaceous earth and the filtrate was dried over Na2SO4. Solvent was removed under reduced pressure. Then the residue was distilled under vacuum (2.5 mm Hg, at 98°-100° C.) to provide 10.08 g of cis-ethyl cinnamate, for a yield of nearly 95%. By GC analysis, this product mixture was found to contain 5.7% over-reduced alkane and 3.5% trans-ethyl cinnamate, but was used without further purification.

Provenance & Evidence