One purpose of a Wittig reaction is the formation of alkenes from aldehydes or ketones employing a carbo-phosphorous ylide, which is stabilized vie resonance to allow for the carbon bonded to phosphorus to be deprotonate from by a base (Ketcha, 142). The resonating ylide will react with the electrophilic carbonyl carbon of its aromatic aldehyde to produce a betaine intermediate, or a crystalized 4
In the separatory funnel, the top layer is the organic solvent and the bottom layer because the aqueous solvent has a higher density thus it sinks. The property of "like dissolves like" can be used to distinguish or to be certain which solvent is on the top or bottom. A few drops of water introduced through the top of the separatory funnel and if the water drops mix with the first layer, then the first layer is the aqueous solvent but if it passes the first layer and goes to the second layer then the bottom layer is the aqueous solvent. However, the aqueous solvent being the bottom layer is not always the case and this can be seen when halogenated solvents such as dichloromethane are mixed with water. Halogenated solvents are denser than aqueous solvents and thus halogenated solvents sink to the bottom.
The reaction above shows the reaction that occurs between salicylic acid, phosphoric acid, and acetic anhydride. First, the phosphoric acid attacks the carbon-oxygen (C=O) of the acetic anhydride which makes it positive. This will make acetic anhydride more prone to nucleophilic attacks. The nucleophile in the reaction is salicylic acid and it was form when oxygen on the phenol group attacked the partial positive charge of a carbon from acetic anhydride.
It forms a complex with HBr and extracts it from the aqueous phase into the organic phase where the alkene is. This dehydrates the acid, making it more reactive so that the addition reaction is possible. Rapid stirring is required in order to maximize the surface area
It was difficult to find an IL that worked well extracting all the N-compounds. In general, it was observed that the nitrogen removal of the synthesized ILs was higher for indole and carbazole than for quinoline (Figure 3). The reason behind this behavior is that quinoline is a Lewis acid, while indole and carbazole are Brӧnsted acids. The imidazolium ILs containing halogen anions showed a good removal efficacy, while the change of anion from chloride IL 1 to dicyanamide IL 2 decreased the extraction efficiency of N-compounds. The presence of double imidazolium rings in the structure of the ILs (ILs 4-5) or aromatic derivatives (IL 7) led to the reduction of the removal properties.
For this reason, pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy) Production Chichibabin synthesis In its general form, the reaction can be described as a condensation reaction of aldehydes, ketones, α,β-unsaturated carbonyl compounds, or any combination of the above, in ammonia or ammonia derivatives. In particular, unsubstituted pyridine is produced from formaldehyde and acetaldehyde Formation of acrolein from acetaldehyde and
The unknowns were correctly identified due to the clear presence of two plateaus in the experimental data. The hot plate was not turned on too high or too low to not obtain one of the three samples, and a sufficient number of values were taken in each part of the distillation before the mixture evaporated away to obtain approximately accurate data for boiling points. The ratio calculated for the volume of solvents in the mixture was .506/.488, where the composition of the mixture was 50.6% acetone, and 48.8% toluene. These two values did not add up to 100% because the GC also recorded some impurities,
Half of this value is 12.63 mL. By interpolating the graph, the pH at this volume was 4.80, which is equivalent to the pKa of acetic acid. According to the tabulated data, the pKa was 4.90 at 15 mL of NaOH. At this point, the change in pH with respect to volume was minimal since these values were far from the equivalence point, which occurred experimentally at 27.41 mL. This can also be seen on the graph as the plateau before the inflection point occured. To calculate the Ka of the acid, the following formula is
As mentioned in number 13, the data for the melting point makes sense because my pure product and given compound almost perfectly matched. 17. Again as explained in number 14, the TLC data made sense because my pure compound and 4-tert-butylbenzyl phenol had similar distances from the solvent origin of the plate. The presence of benzyl bromide and benzyl alcohol also explains how not all the product dissolved in the filtrate.
In green chemistry, innocuous chemical such as hypochlorous acid, HOCl will be used in oxidation, as to reduce the harmful waste. Green chemistry is the name given to modifications implemented in chemical manufacturing processes that ensure a safer and cleaner
The experiment consisted of a Diels Alder reaction between anthracene and maleic anhydride to produce 9,10-dihydroanthracene-9,10-α,β-succinic anhydride. This is called a cycloaddition reaction because the reaction between the two products creates a cyclic product. The conjugated diene (called diene) was anthracene (consisted of 2 double bonds) and the dienopile was maleic anhydride (consisted of 1 double bond). The reaction occured between the alkene group of maleic anhydride and the alkene group of anthracene. The reaction is: Source: Melvil, 2014.
The objective of this experiment was to use an aldol condensation reaction to synthesize 3-nitrochalcone from 3- nitrobenzaldehyde. This was accomplished with a Diels-Alder reaction that utilized 3-nitrobenzaldehyde, acetophenone, ethanol, and sodium hydroxide. The mechanism for the synthesis of 3-nitrochalcone is presented in Figures 1 and 2. The alpha carbon on the acetophenone is deprotonated. This is followed by the attack of the alpha carbon anion on the carbonyl carbon on the 3-nitrobenzaldehyde.
Observations The purpose of this experiment was to be able to synthesize triphenylmethyl bromide from triphenylmethanol by a trityl carbocation intermediate. During the experiment, 0.100 g of triphenylmethanol was placed into a small test tube. The triphenylmethanol looked like a white powder. Next 2 mL of acetic acid was added to the test tube and the solution turned a cloudy white color.
The purpose of this lab is to use the Diels-Alder reaction to combine anthracene and maleic anhydride. Named after its two founders the Diels-Alder reaction is the addition of a conjugated diene (electron rich compound) with a dienophile (electron poor compound). (1) These compounds will be combined using [4+2] cycloaddition, where the numbers 4 and 2 come from the number of π electrons that are used in each compound to synthesize the product. (2) This experiment comes at the cost of losing two π bonds to form two new sigma (σ) bonds in the cyclic compound. (2)
The purpose of this lab was to be able to use physical characteristics to determine the identity of an unknown compound. The data from this experiment classified aluminum as metallic; ascorbic acid, paraffin, palmitic acid, sucrose, graphite, and water as molecular; sodium chloride as ionic. In order to determine this, 3 tests were conducted. The first test was to test the conductivity of each substance at room temperature. In this test, only graphite and aluminum conducted.