Lidia Santiana Palha s3333523 Experiment 2: Williamson Ether Synthesis of 2-octadecyloxynaphthalene Demonstrator: P. Kabauri Date of experiment: 26-09-2017 Summary: In this experiment, 2-octadecylooxnapthalene was synthesized. The synthesis consists of making 2-naphthol solution with acetonitrile. Then CsCO3 and bromooctadecane was added to the solution. And at the end we crystalized it and found out the melting point which ranged from 64-68°C. Theory: In order for an ether to be produced we needed an aroxide ion and an alkyl halide. The reason why we use acetonitrile is because it acts as a solvent and ions can form in it. CsCO3 when added into acetonitrile it forms Cs+ ions and carbonate ions. Also the acetonitrile does not react in the reaction and hence does not interfere with the reaction. …show more content…
The 2-naphthol is very acidic, and therefore can function as an acid, and in the presence of a strong base, CsCO3 ,(See diagram below), the lone pairs of electrons on the oxygen in CsCO3, is going to take the proton from 2-napthol (O-H), and the electrons from the proton are going to move into the oxygen. Then we will have 3 lone pairs of electrons on the oxygen of 2-napthol giving it a -1 charge and hence aroxide ion is
The theoretical weight was 599.6 mg. This yields a percent yield of 3.7%. Table 1 also illustrates the experimental melting point of 99.3-102.1◦C. A melting point that has a range larger than 3◦C is indicative of impurities in the sample. A few possibilities of impurities could have been unreacted norbornene, and water. Evidence that supports that there was unreacted norbornene in the final sample was the fact that the product was a jelly-like structure. Norbornene by itself has a jelly-like structure. However, once norbornene reacted with the acid-catalyst (H2O2), then it should have changed the chemical structure of the molecule and once the solution was brought back down to room temperature, crystals should have formed. Since a jelly-like, or oil-like product was present at the end of the reaction, then this is indicative that there was unreacted norbornene in the sample. The second impurity that may have been present in the final product was water. Instead of adding 3 mL of sodium bicarbonate and then 3 mL of brine, 3 mL of brine was added first and then 3 mL of sodium bicarbonate was added. This experimental error caused excess aqueous solution to be added to the diethyl ether. Since excess water was added to the final product, about 4x the amount of anhydrous sodium sulfate was needed in order to remove the water from the product. This was another indication that there was too much water in
In addition to this, these compounds also display antagonist activity to calcium 23. For this reason, and for their associated pharmacological properties, a lot of interest and attention has been drawn to them in the recent years by researchers 22. A couple of methods have consequently been developed for the preparation of the octahydroquinazolinone derivatives 2. The most common of which include the Biginelli one pot reaction that involves urea/ thiourea, aromatic aldehydes and dimedone 24. Other methods include synthesis with the help of catalysts like concentrated sulfuric acid, Nafion-H, ionic liquid, and TMSCI 24. Synthesis in low ethanol could also be adopted but it is characterized with product yields that are between 19-69% and these are
The percent yield was 26%, and the melting point of the product was 170c-172c. According to these results, it can be considered that there are a high range of reactant in the product because the melting point for Ferrocene is 172 and for Acetylferrocene is about 81-83. It is also showed that the product is not pure, and also the TLC was run.
found to have a melting point of 138 degrees (C). As before, of course this
The Diels-Alder experiment was conducted in laboratory to produce a bridged polycyclic anhydride. The Diels-Alder reaction takes place to combine a diene; the electron rich nucleophile with a dienophile which is “diene loving”, with at least one strong electron-withdrawing group1. In this experiment, anthracene is used as the diene which combines with maleic anhydride, the dienophile, to form
Abstract In this experiment methyl-3-phenyl-2-propenoate was prepared using a Wittig reaction. Benzaldehyde and methyl (triphenylphosphoranylidene) acetate were used to give a final product. 0.33g of methyl3-phenyl-2-propenoate was found at the end of the experiment therefore the percentage yield of methy-3-phenyl-2-propenoate is 62%. The Rf value of benzaldehyde was found to be 0.85.
The presence of ethylbenzene complicated the analysis of results because the increased appearance of ethylbenzenes as a product of o- and p-trifluromethylstyrene and m-nitrostyrene was inversely related with a decrease in the yield of α alcohol. The author concluded that the product of ethylbenzene was due to competing reactions taking place. 4. The α hydrogen in p-nitrotoluene would be more acidic than the α hydrogen in m-nitrotoluene because the conjugate base of p-nitrotoluene has more resonance allowing for a greater delocalization of the charge and more stability.
There are three steps that occur in the synthesis of acetaminophen. First is the nitration of phenol, where phenol (hydroxybenzene) reacts with sodium nitrate, which is an oxidizing agent, while in the presence of sulfuric acid. This produces a mixture of structural isomers of nitrophenol. The second step is the reduction of a nitro group to an amine. In this case, oxygen is lost from the nitro group of 4-nitrophenol and a hydrogen is added to form 4-aminophenol, an amine.
These crystals’ melting point was then determined, concluding the
This lab is all about analyzing substances in terms of their physical and chemical changes. The physical properties of a substance can be observed and measured without changing the composition of the substance. It can be used to identify and describe substances. Physical properties of matter include odor, color, density, solubility, boiling point and melting point, and its physical state at room temperature. A colorless, odorless liquid that freezes at 0°C and boils at 100°C is probably water, for example. Every substance also has chemical properties. Chemical properties, however, are observed only when a substance undergoes a change in composition – a chemical reaction. Each of the substances involved in this lab will undergo physical and/or chemical changes.
Discussion: In the experiment of enzyme kinetics, inhibition and concentration of substrate were investigated. The effect of these two factors will be determined through an experiment of four different concentrations of the inhibitor, and five different concentrations of substrate. Figures 2, 3, 4, and 5 provide an observation for the change in absorbance with time in the presence of different concentrations of inhibitor, and in the absence of inhibitor (phosphate).
Once reaching a constant mass after driving of the excess diethyl ether, the crude product had a mass of 0.327grams and a high percent yield of 97.8%. During the first TLC examination of the crude product it was found to have 3 spots on the plate, biphenyl, benzaldehyde, and benzhydrol with Rf values of 0.68, 0.36, and 0.10 respectively. It was expected to see benzhydrol, the product, and biphenyl, the impurity, on the plate, but the presence of benzaldehyde was telling that not all of the starting material had been consumed during
C1. The.. Volume of NaOH calculated for a preparation buffer of 0.10 M sodium acetate to 4.80 pH. The first step has a net charge of +1, the second step has a net charge of 0, the third step has a net charge of -1 and the last step has a net charge of -2. The zwitterion is the second figure, as its net charge is zero. pI=(pKa)/2=(2.1
Abstract: Luminol, known for it’s use in crime labs to identify blood, was one of the main components used in the experiment which sought to use a starting material, convert it to a product, and then use the product as the starting material for an alternate reaction. In the experiment conducted in lab, 5-nitro-2,3-dihydropthalazine-1,4-dione was used as starting material, and when the nitro group was added to sodium hydrosulfite in 3M sodium hydroxide in water it was reduced and the resulting amine was used as a starting material to investigate properties of luminol. Chemiluminescence’s release of glowing light was due to the breaking of bonds brought upon by the excitation of electrons to release energy, and this resulting glow produced is
Equilibrium in the reaction can be shifted towards the formation of the addition product by using sulfuric acid to drive the reaction.