How do you make benzaldehyde from dibenzalacetone?

How do you make benzaldehyde from dibenzalacetone?


  1. Add 10ml of freshly distilled benzaldehyde and 20ml of acetone to a conical flask.
  2. Place the flask in a cold bath of water and then, with regular stirring, add 2.5ml sodium hydroxide dropwise.
  3. Keep the temperature at 30 oC.
  4. stir the mixture for 2 hours after the complete addition of sodium hydroxide.

How many molecules of benzaldehyde resulted in the formation of dibenzalacetone?

a) Two molecules of benzaldehyde and one molecule of acetone reacts and result in one molecule of dibenzalacetone where sodium hydroxide in aqueous…

How do you make dibenzalacetone?

Dibenzalacetone has been prepared by condensing benzaldehyde with acetone using as condensing agents dry hydrogen chloride,1 10 per cent sodium hydroxide solution,2 and glacial acetic acid with sulfuric acid.

What type of reaction is the synthesis of dibenzalacetone?

aldol condensation
Dibenzalacetone can be synthesized from benzaldehyde and acetone through crossed aldol condensation. The reaction is given below. This reaction is also called the Claisen-Schmidt reaction. It is the reaction of a ketone with an aromatic aldehyde that does not contain any alpha hydrogens.

Is formed as a intermediate While preparation of dibenzalacetone from benzaldehyde?

Principle: When an ethanolic solution containing acetone and its two equivalents of benzaldehyde is made alkaline with sodium hydroxide, rapid condensation occurs with the formation of dibenzal-acetone, or dibenzylidene-acetone.

What is the chemical formula of benzaldehyde?


How do you recrystallize dibenzalacetone?

The dry product from the previous lab period will be recrystallized by using about 20 mL of hot, boiling 95% ethanol. After dissolving, crystals should reform as soon as the solution cools to room temperature (without the aid of ice).

What is the theoretical yield of dibenzalacetone in your synthesis?

If the theoretical yield is 1.998 mmols, multiplying this by the molecular weight of the product dibenzalacetone gives the theoretical yield as a mass: (0.001998 mols x 234.18 g/mol) = 0.468 g.

What is the purpose of synthesis of dibenzalacetone?

Aldol condensation is an important route of organic synthesis because it provides an efficient way to form carbon-carbon bond. In this condensation an enol or enolate ion reacts with a carbonyl compound to form a β-hydroxyketone or β-hydroxyaldehyde which is then followed by dehydration.

What will be the product obtained when one equivalent of benzaldehyde reacts with one equivalent of acetone?

The condensation reaction between one equivalent of acetone and two equivalents of benzaldehyde in presence of dilute alkali leads to the formation of. Benzalacetophenone.

How is benzaldehyde formed?

Industrially, benzaldehyde is made by a process in which toluene is treated with chlorine to form benzal chloride, followed by treatment of benzal chloride with water. Benzaldehyde is readily oxidized to benzoic acid and is converted to addition products by hydrocyanic acid or sodium bisulfite.

What happens when benzaldehyde is exposed to the atmosphere?

Benzaldehyde readily undergoes autoxidation to form benzoic acid on exposure to air at room temperature. It is confirmed that benzyl alcohol (and a number of other alcohols), even at low concentrations in benzaldehyde, inhibits the autoxidation.

How is dibenzalacetone formed from acetone and benzaldehyde?

The product dibenzalacetone was formed from the reaction between an acetone molecule and two benzaldehyde molecules. Generally, the aldol condensation is carried out under a base condition. Sodium hydroxide was mixed with distilled water then was used to react with sufficient ethanol as the first step.

What is the reaction between benzalacetone and hydroxide?

The benzalacetone tends to form benzalacetone enolate ion after the hydroxide group from the surrounding attack the proton which attached to the carbon at benzylic position. The same process has been take place as in the Diagram 2 but with the more bulky benzalacetone enolate ion as the material.

What is the percentage yield of dibenzalacetone in this experiment?

The percentage yield of dibenzalacetone in this experiment is 83.27%. Some of the product has been lost during the process of recrystallization. In recrystallization, some of the product dissolved in the ethyl acetate. The melting point of the product is lower than the actual melting point (110 °C ~ 111 °C).

What is the melting point of dibenzalacetone after recrystallization?

In recrystallization, some of the product dissolved in the ethyl acetate. The melting point of the product is lower than the actual melting point (110 °C ~ 111 °C). This is because there is some impurities exist in the particular compound which will tend to lower the melting point of the dibenzalacetone.