Exp 5 - Exp 5 Charge a 5mL conical vial with ~.2g of...

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Exp 5 Charge a 5mL conical vial with ~.2g of dibenzyl ketone (d=1.068 g/mL), .2g of Benzil, and 1.5 mL of absolute ethanol. Insert a spin vane o point down will keep the solid in suspension and usually avoids bumping Attach an air-condenser Place an al. block beneath the vial Heat the rxn mixture to gentle reflux ~10 minutes o Observe bright yellow color After both compounds have been completely dissolved, (w/ a syringe!) add ~.2mL of ethanolic potassium hydroxide (KOH) solution drop wise to the gently boiling rxn mixture. Heat for 10 minutes for color change. o The color should change from yellow to dark purple immediately. o KOH is the catalyst o It is important that both ketones are dissolved before the catalyst is added, because benzil is a better electrophile in the reaction but only able to react at a reasonable rate in a solution. From previous experiment, we know that benzil does not dissolve well in cold ethanol, which makes it necessary to reflux the mixture in order to increase its solubility. Cool down the mixture to RT o A very dark precipitate usually forms after a few minutes into the reaction. o
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Exp 5 - Exp 5 Charge a 5mL conical vial with ~.2g of...

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