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
As a final point, the unknown secondary alcohol α-methyl-2-naphthalenemethanol had the R-configuration since it reacted the fastest with S-HBTM and much slower with R-HBTM. TLC was a qualitative method and ImageJ served as a quantitative method for determining which reaction was the faster esterification. Finally, 1H NMR assisted in identifying the unknown from a finite list of possible alcohols by labeling the hydrogens to the corresponding peaks.
In a small reaction tube, the tetraphenylcyclopentadienone (0.110 g, 0.28 mmol) was added into the dimethyl acetylene dicarboxylate (0.1 mL) and nitrobenzene (1 mL) along with a boiling stick. The color of the mixed solution was purple. The solution was then heated to reflux until it turned into a tan color. After the color change has occurred, ethanol (3 mL) was stirred into the small reaction tube. After that, the small reaction tube was placed in an ice bath until the solid was formed at the bottom of the tube. Then, the solution with the precipitate was filtered through vacuum filtration and washed with ethanol. The precipitate then was dried and weighed. The final product was dimethyl tertraphenylpthalate (0.086 g, 0.172mmol, 61.42%).
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
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
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
found to have a melting point of 138 degrees (C). As before, of course this
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.
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
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.
The percentage yield gained was 70% from the Fischer Esterification reaction, which evaluates to be a good production of yield produced as the reaction is known to be reversible where conditions such as the concentration of the reactants, pressure and temperature could affect the extent of the reaction from performing. These white crystalline crystals were tested for impurity by conducting a melting point analysis and taking spectrospic data such as the IR spectra, HNMR and CNMR to confirm the identification of the product. These spectrospic methods and melting point analysis confirmed the white crystalline crystals were benzocaine.
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
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
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
Advantages of alkene preparation through dehydrohalogenation of alkyl halides under basic conditions are that the reaction will not produce the products formed thermodynamically, only the kinetic products will be collected. Based on the results produced in the laboratory experiment the functional groups in the substrate can be changed by the strength and the amounts of the solvents used. The efficiency of the reactions are as expected. Side reactions that have the possibility of occurring are due to changes in thermodynamics, kinematics, or in the strengths and amounts of the solvents used.