Dihydropyrimidinones Lab Report

In the first step, the leaving group departs, forming a carbocation C+. In the second step, the nucleophilic reagent (Nuc :) attaches to the carbocation and forms a covalent sigma bond. If the substrate has a chiral carbon, this mechanism can result in either inversion of the stereochemistry or retention of configuration. Usually both occur without preference. The result is racemization.

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

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.

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

3- Then add drops of an acyl chloride solution which was obtained from the first step. 4- Add HCl acid (acidizing agent) after completing the reaction. 5- layering; concentrating under a lower pressure, add residues into an alcohols solvent for dissolution, add drops of H2O to separate out flucloxacillin crystals

It is type of condensation reaction, which involve the condensation of acidic anhydride and aldehyde in the presence of weak base (i.e. Sodium and potassium salt of the acid or trimethylamine) to give unsaturated carboxylic acid.(Equation-1)[1].In 1968 Perkin described the very first example of such type condensation reaction, involve the synthesis of coumarin by condensing the sodium or potassium salt of salicylaldehyde with acetic anhydride (Equation-2)[2].Generally such type of reaction is only applicable to aromatic aldehyde and useful for the preparation of substituted cinnamic acid (Equation-3)[3] Equation-1 Equation-2 Equation-3 In 1883.A very important variation is done by plӧchl, which involve the heating of benzaldehyde

Like isoquinoline, quinoline also coupled effectively with substituted benzoyl under identical conditions. The reaction went to completion in 2 h and the desired acyl addition product, 5a, was obtained in 76% yield (Scheme 4, Table 3) A plausible mechanism for the synthesis of an isoquinolin-1-yl-arylmethanone is depicted in Scheme 5. The synthetic cycle is assumed to begin with the reaction of Aliquat 336 as the phase transfer catalysis and K2S2O8 as a dehydrogenative reagent to generate the salt A, which then would convert to the sulfate radical B by heating. Sulfate radical B could react with the benzyl alcohol 1a through a hydrogen abstraction process providing an acyl radical C. Further addition of acyl radical C to the isoquinoline 1a

The main objective of this experiment was the formation of phenacetin from the synthesis of acetaminophen. This was done through a chemical reaction known as the Williamson ether synthesis using techniques of refluxing, vacuum filtration and recrystallization incorporating a mixed solvent system. A further objective of this experiment was to study the formation of the product (phenacetin). Such validation was completed by using techniques for determining the melting point, calculating percent yield, and IR (infrared spectroscopy) of the resultant product.

The process uses a base carbon dioxide and acid work-up. The original reaction done by Kolbe involved the formation of sodium phenoxide through the evaporation of a molar equivalent mixture of phenol and aqueous sodium hydroxide. The hygroscopic sodium phenoxide is then heated while carbon dioxide gas is passed over the molten salt. The mixture is then further heated to give the dianion of salicylic acid along with carbon dioxide and phenol both of which distill away from the mixture.

The pKa of this unknown weak acid is 4.0 and the Ka is 1.0 x 10-4 mol dm-3 while the molecular weight is 166.67 g mol-1. It is closely related to the ascorbic acid with a pKa of 4.10 and a Ka of 7.9 x 10-5 with a molecular weight of 176.12 g mol-1. Therefore it can be concluded that the unknown acid is ascorbic acid. Titration technique is best suited for this experiment because the end point and equivalence point can be distinguished by the physical changes which are the colour change of the mixture. We are also able to better control and determine the volume of NaOH in the burette needed to neutralise HCI, CH3COOH and the unknown acid.

This is beneficial for reactivity because the nitrogen in -NH2 in aniline is able to delocalize the positive charge of a carbocation by donating its electrons to the carbon during the transition state when aniline is brominated. The next strongest substituent would be -OH in phenol, followed by -OCH3 in anisole. This is because the three hydrogens on the carbon make the carbon slightly electronegative, slightly pulling away the electrons surrounding the oxygen directly attached to the benzene ring. The least reactive substituent would be -NHCOCH3 in acetanilide because the highly electronegative oxygen pulls away electrons from the nitrogen directly attached to the benzene ring, making the nitrogen less willing to stabilize the carbocation in the transition state in an electrophilic aromatic substitution reaction. Since all of the substituents are orth, para-directos, bromine in a bromination reaction would be substituted at either the 2 carbon, 4 carbon, 2 and 4 carbon, 2 and 6 carbon, or 2, 4, and 6 carbon.

A signal at this wavenumber indicates that there is an ester group present in this sample of Isopentyl Acetate. According to the structural formula of Isopentyl Acetate, a carbonyl group is present in its structure. The final of the three signals was present at a wavenumber of 1,239.88 cm^-1 . A signal at this wavenumber indicates that there is a carbon-oxygen group present in this sample of Isopentyl

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.