Synthesis Of DibenzalacetoneEssay Preview: Synthesis Of DibenzalacetoneReport this essayExperiment2: Preparation of DibenzalacetoneUsing the cabon-cabon bond making ability in carbonyl chemistry, Dibenzalacetone is synthesized from 2 equivalent of benzaldehyde and 1 equivalent of acetone in a base catalyzed reaction.
Physical Data1: *detailed risk and safety phrases are attached.substanceHazards, risks and safety practicesMW (g/mol)Amt. Usedmp (K)bp (K)density(g/cm^3)acetoneR11, R36, R67, S9, S25, S2658.080.24 g0.004178.2329.4benzaldehydeR22, S24106.130.82 g0.008451.11.0415ehtyl acetateR11, R36, R66, R67, S16, S26, S3388.112 ml per gram189.55350.250.897R35,S22, S26, S38, S45, S62, s24/2539.9970.4 gEthanolR11, S2, S7, S1646.07158.8351.60.789Dibenzalacetone234 g/molunknownunknownTheoretical Yield:Limiting reagent: acetone (0.004 mol)Presuming 100 % of limiting agent makes dibenzalacetoneDibenzalacetone (100% yield) = 0.004 mol * 234 g/mol = 0.936 gramThe theoretical yield of dibenzalacetone is 0.936 gramProcedures:In a 50 ml conical flask sodium hydroxide (0.4g, 0.01 mol), distilled water (2 ml) and ethanol (2ml, 95%) were mixed into a clear solution. The solution was then cooled to room temperature. Benzaldehyde (0.8ml; 9.82g, 0.008mol) was then added to the solution followed by addition of acetone (0.3ml; 0.24g, 0.004mol) and formed into a thick yellow solution. The flask was then swirled gently and constantly for 5 minutes. This turned into a fluffy precipitate as the flask was swirled. After 5 minutes of constant swirling, the flask was swirled once or twice every minute for 10 minutes thereafter. Ethanol (95%) was cooled in ice bath while the fluffy precipitate in the 50 ml conical flask was collected using a small buchner funnel. The fluffy precipitate was washed with distilled water (approximately 500 ml) followed by ethanol (approximately 2ml, 95%). The washing produced a clear filtrate solution and a yellow precipitate. The washed precipitate was then left to air dry for a week in a clean 50 ml beaker forming a lumpy yellow solid. Which was then weighted and recrystallised in ethyl acetate (approximately 2ml) to afford dibenzalacetone, a shiny powedery yellow solid ( 0.4377g, 46.8%, m.p 107-109, literature m.p. 110-1112).
Product calculations for Adol formation of DibenzalacetoneWeight of the receiver flask = 16.2662 gReceived flask + product = 16.7039 gNett weight = 0.4377 gTheoretical yield =0.936 gPercentage yield = 46.76%Product characteristicsBP = 107 — 109 (Celsius)Lit. BP = 110 — 111 (Celsius)2Infrared spectrum table3:*the IR spectrum of dibenzalacetone is attachedAbsorption (per cm)1338-981Intensitymedium, sharpmedium, sharpvery strong, sharpvery strong, very sharpall strong and sharpDescriptionsp and sp2 C-H streches, alkene, arene. This confirms the two rings and 2 double bonds in our moleculealdehyde C-H strech, aldehyde shouldnt be present but aldehydes are very similar to ketone which is present.C=O stretch. This is a very useful peak as it is very diagnostic which also confirms the presence of ketone.C=C stretch, This could be from the alkene and benzene ring in the molecule. A very strong intensity indicates presence.A lot of different things are absorbed at this region thus although the signals are strong, its best ignored.DiscussionThe key to this experiment is the aldol reaction4 that results in a C-C bond forming reaction. From observation it seems this reaction can be used to synthesis very large organic molecules. The concept of this reaction revolves around the idea having the α-carbon of an aldehyde or ketone attacking the carbonyl carbon of another aldehyde or ketone. The result of this attack is a new C-C bond being formed.
The О±-carbon of the acetone in our experiment gets deprotonated easily in NaOH revealing an О±-carbon with a lone pair of electron attached to it. This О±-carbon is a very good nucleophile, a very good lewis acid and is extremely reactive. In other word we have turned our acetone into an anion. This anion likes to attack and form a covalent bond with a carbonyl carbon. This is due to the positive nature of carbonyl carbon and the electronegativity of the oxygen , most of the electron in a carbonyl molecule is around the oxygen thus leaving the carbon bare and susceptible to nuecleophilic attack. As a result of this attack, a molecule is yielded with both aldehyde and alcohol functional groups, hence the name aldo reaction. The product
The molecule to be hydrogenated
Ayl-alcohol is a very nice molecule to possess aldehyde and alcohol, but is only a very small molecule and will not give you a strong reaction like a covalent bond of a carbonyl carbon. It is the simplest molecule in the universe; and most would not even consider the element to be an important ingredient in one’s food. Even better, as there is a lot of chemistry there is much less to do at work than aldehyde and alcohol. It is also quite expensive, which makes it even harder to obtain, if you ever want a good deionized solution for such a small molecule.
There are so many questions still to deal with here; how are the reactions between aldehydes and phenyl alcohols work, what is produced, how does the carbonation work, what is the catalytic power of acetone? What is a cyridophore of acetaminobutyric acid?
Since most aldehydes have low efficiency and low energy, a few factors will hold up in your recipe; a few things could lead to errors by you and in the first place you have to do a little thought about how much it will add to an otherwise bland ingredient and what type of reaction will be appropriate. An acetone molecule can also be very complex; you must first of all check out the type of acetone molecule and its physical properties to find that one looks right, but secondly you must do a few experiments for the next two recipes so that you can get a good idea of the chemistry.
The key to getting a good idea of the chemistry of acetone is getting high quality cation. So you should have the ingredients already at the moment you are making the acetone. Most likely you will be making a small amount of the acetone at home for your children’s play events in their small kitchen before going to the next two batches of your food. If you happen to have children to play the next two batches while you make your anion and are interested in making some of them more it might be convenient for you to prepare an acetone for your children’s play event.
One last fact: you must have an anion with a carbonyl carbon, which will be the one you will use when you make your anion. In most laboratories the product would just be an indiquated carbon. This is because the anion form has a very low deionizing power, while the one made of this anion could give you a stronger reaction. That is why it is recommended to use one of these cations and that they be carefully separated from the other as they contribute to the creation of the anion form.