27 March 2015
Date the practical was carried: 18 November 2014
Name: Justyna Nalepa
Student Number: 10031543
Experiment 1: HYDROLYSIS OF PHENYL BENZOATE
Introduction:
In general definition, hydrolysis is chemical conversion in which organic molecule, react with water, resulting formation of new covalent bond with OH and break of covalent bond with living group on the original molecule (Mill and Mabey, 1988).
Esters conversion to carboxylic acids is an essential reaction with wide-used applications in both industry and research (Lovric M. et all., 2007). Ester hydrolysis is reversible reaction and occur in both either acid or base condition. Following experiment take place in base catalysis, where carboxylic acid formed reacts next with the hydroxide to produce the RCOO--the acid anion. Once in the first reaction acid is created and in the second reaction is eliminated, therefore all the ester transformed into its hydrolysis product.
The hydrolysis of phenyl benzoate and of phenol esters generally is of particular interest, because both products of hydrolysis are acidic in type: acid- benzoic acid and alcohol- phenol. Fallowing experiment is carried out in potassium hydroxide,
C6H5COOC6H5 + H2O = C6H5COOCH + C6H5OH where both compounds remain in solution as their potassium derivatives. They have been, however separated by acidifying the solution ( in order to liberate both acid and phenol) and then adding an excess of sodium carbonate. The benzoic acid readily displaces
Different procedures were used to isolate benzil from the ether layer and benzoic acid from the aqueous layers. To isolate benzil, anhydrous MgSO4 was added to the flask containing the ether layer solution. MgSO4 removes the remaining water in the ether layer solution. After making sure that enough amount of MgSO4 present in the solution, the ether solution was filtered by using gravity filtration. During filtration, MgSO4 was removed from the solution and the ether solution was collected in 25 ml flask. To separate benzil from the filtered ether solution, the beaker containing the ether solution was heated until the ether evaporated. After letting the beaker to cool to room temperature, the mass of the beaker with the benzil crystals was measured. From the combined mass of the beaker and the benzil crystals and from the predetermined mass of the beaker, the mass of the collected crystals was calculated to be 0.266 gram.
This way, cyclohexane is converted to adipic acid or hexanedioic acid. Since the product is soluble in hot water, the two-phase systems (organic cyclohexane and aqueous hydrogen peroxide) slowly become a single aqueous phase. In the end, only H2O2 and cyclohexene can be changed, tungstate and the phase transfer catalyst can be tapped and reused. The phase transfer catalyst used were a mixture of aliquat 336 and potassium hydrogen sulphate.
Salicylic acid was esterfied using acetic acid and sulfuric acid acting as a catalyst to produce acetylsalicylic acid and acetic acid. The phenol group that will attack the carbonyl carbon of the acetic anhydride is the –OH group that is directly attached to the benzene since it is more basic than the –OH group attached to the carbonyl group. This method of forming acetylsalicylic acid is an esterification reaction. Since this esterification reaction is not spontaneous, sulfuric acid was used as a catalyst to initiate the reaction. Sulfuric acid serves as the acid catalyst since its conjugate base is a strong deprotonating group that is necessary in order for this reaction to be reversible. The need for the strong conjugate base is the reason why other strong acids such as HCl is not used since its conjugate base Cl- is very weak compared to HSO3-. After the reaction was complete some unreacted acetic anhydride and salicylic acid was still be present in
The sodium hydroxide acts to pull the hydrogen off the oxygen in the 2-methylphenol so that the oxygen has a negative charge and can attack the sodium chloroacetate. Again, using a 1:1 molar ratio, 0.34 g (2.9 mmol) of sodium chloroacetate (the good leaving group) was added to 1 ml of water and dissolved. Following dissolving all of the 2-methylphenol (to avoid the sodium hydroxide reacting concurrently with the sodium chloroacetate and 2-methylphenol) in the sodium hydroxide, the aqueous solution of sodium chloroacetate was transferred to the reaction flask. This mixture was then heated to reflux, using a medicine dropper affixed to the top of the flask as an alternative method to boil without
3) Hydrolysis - Water used to breakdown molecules. Hydro means water and lysis means to breakdown. An example of hydrolysis in action within our bodies is how our body breaks down protein into amino acids. Water is used to break protein down in to its amino acids.
The purpose of this experiment was to practice the functional group transformation procedure. The process of the experiment included the dehydration of 2-methylcyclohexanol in the presence of phosphoric acid and heat. The products that were formed from the reaction were 1-methylcyclohexene and 3-methylcyclohexene. The mass of the final product solution was 0.502g with a percent yield of 18.7% and a boiling point range of 84.5-98.5oC.
In this experiment, the Fischer Esterification of an unknown acid and an unknown alcohol was used to prepare an unknown ester. Sulfuric acid was used as a catalyst in the reaction which then was put under reflux. After cooling, the pH of the solution was raised to approximately 8 using sodium carbonate. Diethyl ether was added, then the aqueous layer was removed and the organic layer was washed with sodium chloride. The aqueous layer was removed again and sodium sulfate was added. The unknown product was then identified using gas chromatography (GC) to obtain the retention time.
6. Purpose: to clarify the mechanism for the cycloaddition reaction between benzonitrile oxide and an alkene, and to test the regiochemistry of the reaction between benzonitrile oxide and styrene; to purify the crude product of either trans-stilbene, cis-stilbene, or styrene reaction.
A pre-weighed (0.315g) mixture of Carboxylic acid, a phenol, and neutral substance was placed into a reaction tube (tube 1). tert-Butyl methyl ether (2ml) was added to the tube and the solid mixture was dissolved. Next, 1 ml of saturated NaHCO3 solution was added to the tube and the contents were mixed separating the contents into three layers. Once this was completed
In this experiment, the main objective was to synthesize a ketone from borneol via an oxidation reaction and secondly, to produce a secondary alcohol from camphor via a reduction reaction. Therefore, the hypothesis of this lab is that camphor will be produced in the oxidation reaction and isoborneol will be the product of the reduction reaction because of steric hindrance. For the oxidation step, a reflux will be done and then a microscale reflux for the reduction step. The products will be confirmed using Infrared spectroscopy, the chromic acid test, 2,4-DNP test and 13C NMR spectroscopy. The results of this
After dissolving benzoic acid in 1.0mL CH2Cl2 and 1.0mL 10% NaHCO3 solution, two layers are created, the top layer is 10% NaHCO3 solution and the bottom is CH2Cl2.
At room temperature (25°C), esterification reactions are relatively slow, therefore requiring the rate of the chemical reaction to be increased for the products to be formed efficiently. This is implemented, by using a catalyst, such as concentrated sulphuric acid (H2SO4 (aq)), as well as by heating the mixture: using a heating mantle. As a result, the energy of the reactants can be greater than the activation energy, increasing the rate of reaction. Hence, as the reactants are relatively volatile, so reflux apparatus such as a pear-shaped flask and a Liebig condenser were used, to minimise the amount of reactants lost, as well as allow the reaction to take place at the highest temperature possible. In addition, boiling chips were added prior to reflux, to prevent bumping and a decrease a loss of volatile reactants, during the reflux
An ester was synthesized during an organic reaction and identified by IR spectroscopy and boiling point. Acetic acid was added to 4-methyl-2-pentanol, which was catalyzed by sulfuric acid. This produced the desired ester and water. After the ester was isolated a percent yield of 55.1% was calculated from the 0.872 g of ester recovered. This quantitative error was most likely due to product getting stuck in the apparatus. The boiling point of the ester was 143° C, only one degree off from the theoretical boiling point of the ester 1,3-dimethylbutyl, 144 ° C. The values of the
In this experiment, a Fischer Esterification reaction was performed with two unknown compounds. The unknown compounds, Acid 2 and Alcohol D, were identified by using the knowledge of the reaction that took place, and the identity of the product that was synthesized. The identification of the product resulted from analysis of IR and NMR spectra.
In this experiment it is aimed to synthesize benzopinacol through photochemical reaction of benzophenone and, benzopinacolone via acid-catalyzed rearrangement of benzopinacol. In this experiment, mixture of benzophenone, isopropyl alcohol and a drop of glacial acetic acid was exposed to sunlight which in turn, undergone photochemical reaction. In this reaction, molecules of benzophenone was brought to n((* triplet state where it possibly abstracted hydrogen from isopropyl