Experiment 02: Synthesis and characterisation of Benzocaine Introduction Benzocaine is described and used in the industry as local external anaesthetic; it is constructed of a white crystalline powder. The advantage of anaesthetics such as benzocaine is the action can be reversible where the use is followed by a completed recovery of the tissue with no potential permanent damage being caused. Aim The purpose of conducting this experiment was to synthesise and characterise for the preparation of benzocaine via a fishcer esterification reaction by the means of amino benzoic acid alongside ethanol. The product was also precipitated from a solution in order to gain a pH of 8.The secondary aim was to esterify the reaction in an equilibrium reaction catalysed via the addition of acid shown below: Experimental Reactants used: 4- Aminobenzoic used: 3.03g (0.018 moles) Ensure gloves are worn at all times when handling strong acids and bases within the experiment of the preparation of benzocaine. 4-aminobenzoic acid (3.0g, 0.022 moles) was suspended into a dry round-bottomed flask (100cm3) followed by methylated sprits (20 cm3). Taking extra care the concentrated sulphuric acid of (3.0 cm3, 0.031 moles) was added. Immediately after the condenser was fitted on, and the components in the flask were swirled gently to mix components. It should be ensured that the reactants of the concentrated sulphuric acid and the 4-aminobenzoic acid were not clustered in the ground glass joint between the condenser itself and the flask. In order to heat the mixture to a boiling point, a heating mantle was used and then further left for gently refluxing for a constituent time of forty minutes. After the duration of the consistent forty minutes the rou... ... middle of paper ... ...rivate and taking into account there boiling point and volatility the Gc retention time will increase, in accordance to the chain going up, so in this case the pentyl derivative would go first then the butyl derivative. Conclusion 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.
The primary goal of this laboratory project was to identify an unknown compound and determine its chemical and physical properties. First the appearance, odor, solubility, and conductivity of the compound were observed and measured so that they could be compared to those of known compounds. Then the cation present in the compound was identified using the flame test. The identity of the anion present in the compound was deduced through a series of chemical tests (Cooper, 2009).
The experimental Fischer esterification of 8.92g of acetic acid with 5.0g of isopentyl alcohol using concentrated sulfuric acid as a catalyst yielded 4.83g (65.3% yield) of isopentyl acetate. The product being isopentyl acetate was confirmed when the boiling point during distillation had similar characteristics to that of the literature boiling points2. Physical characteristics like color and smell also concluded a match of our product with what was intended. 1H-NMR spectroscopy analysis supported this claim due to the fact that the integration values and chemical shifts were comparable to isopentyl acetate. Lastly, infrared spectroscopy (IR) showed similar key characteristics of our product’s wavelengths to that of pure isopentyl acetate5.
The boiling point of the product was conducted with the silicone oil. Lastly, for each chemical test, three test tubes were prepared with 2-methylcyclohexanol, the product, and 1-decene in each test tube, and a drop of the reagent were added to test tubes. The percent yield was calculated to be 74.8% with 12.6g of the product obtained. This result showed that most of 2-methylcyclohexanol was successfully dehydrated and produced the product. The loss of the product could be due to the incomplete reaction or distillation and through washing and extraction of the product. The boiling point range resulted as 112oC to 118oC. This boiling point range revealed that it is acceptable because the literature boiling point range included possible products, which are 1-methylcyclohexene, 3-methylcyclohexene, and methylenecyclohexane, are 110 to 111oC, 104oC, and 102 to 103 oC. For the results of IR spectroscopy, 2-methylcyclocahnol showed peaks at 3300 cm-1 and 2930 cm-1, which indicated the presence of alcohol and alkane functional group. Then, the peak from the product showed the same peak at 2930 cm-1 but the absence of the other peak, which indicated the absence of the alcohol
The goal of this lab is to exemplify a standard method for making alkyne groups in two main steps: adding bromine to alkene groups, and followed by heating the product with a strong base to eliminate H and Br from C. Then, in order to purify the product obtained, recrystallization method is used with ethanol and water. Lastly, the melting point and IR spectrum are used to determine the purity of diphenylacetylene.
ester, and we produce the most acid and alcohol. In bottle 3 we still have a good
The dehydration of 1-butanol is different in comparison. The sulfuric acid does make the hydroxyl group a good leaving group as it does for 2-butanol, but the result is a very unstable primary carbocation.
In this experiment, an acid (Benzoic acid), a base (Ethyl 4- Aminobenzoate) and a neutral compound (9-Fluorenone) were extracted from a mixture. HCl was the acid used to separate the base from the mixture, by forming an organic layer, which contained the acid, the neutral compound, and an aqueous layer that contained the base. NaOH was the base that was used to separate the acid from the neutral compound, which resulted in an organic layer containing the neutral compound and an aqueous layer containing the acid. After this a base was then added to the first aqueous layer containing the base, and an acid added to the second aqueous layer containing the acid. The percent recovery of each compound was then evaluated. The basic component, Ethyl
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.
The spots moved 3.8cm, 2.3cm, 2.1cm, 1.8cm, and 2.5 cm, for the methyl benzoate, crude product, mother liquor, recrystallized product, and isomeric mixture, respectively. The Rf values were determined to be.475,.2875,.2625,.225, and.3125, for the methyl benzoate, crude product, mother liquor, recrystallized product, and isomeric mixture, respectively. Electron releasing groups (ERG) activate electrophilic substitution, and make the ortho and para positions negative, and are called ortho para directors. In these reactions, the ortho and para products will be created in a much greater abundance. Electron Withdrawing groups (EWG) make the ortho and para positions positive.
The purpose of this lab was to better understand how the vibrational frequencies of five different compounds were affected by the molecular shape as well as substitution. We were able to determine this using an IR spectrum of each compound as well as by predicting the vibration frequencies by using Gauss View. Furthermore, students were also able to demonstrate their skills in reading IR spectrums.
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%).
Benzyl bromide, an unknown nucleophile and sodium hydroxide was synthesized to form a benzyl ether product. This product was purified and analyzed to find the unknown in the compound. A condenser and heat reflux was used to prevent reagents from escaping. Then the solid product was vacuum filtered.
When benzoic acid paired with 1.0 M NaOH, it was observed that both compounds were soluble. Upon the addition of 6.0 M HCl into this solution, benzoic acid became insoluble. Benzoic acid was also insoluble in 1.0 M HCl. Ethyl 4-aminobenzoate was found to be insoluble in 1.0 M NaOH and soluble in 1.0 M HCl. But then, after adding 6.0 M NaOH into the test tube C (mixture of ethyl 4-aminobenzoate and 1.0 M HCl), a white powdery solid (undissolved compound) was formed. These demonstrate that both the acid and base became more soluble when they were ionized and less soluble when they were
Reflux is an isolation technique that heats a reaction mixture to produce a distillate that travels up a reaction vessel and is cooled using a reflux condenser (Figure 2, Report) and cold water, which will condense the distillate back into the reaction vessel. The piperine was in this liquid portion of the reaction mixture. The condensate was filtered away from the black pepper and reduced to a yellow, powder residue under a stream of nitrogen and a hot water bath. The residue was dissolved in potassium hydroxide and ethanol and then precipitated with the addition of DI water. The precipitant was filtered away and this concluded the isolation of the crude piperine product. The purification of piperine was done by recrystallizing the crude product in a hexanes/acetone solvent mixture and the crystals filtered away from
It is in this light that a clear guideline for safety and protection in the chemistry lab has been formulated (Society, 2003). The basic safety rules for chemistry lab are highlighted as personal conduct, personal safety, hygiene practices, chemical handling, equipment handling and emergency response. Jewelry and other accessories are prohibited and should not be worn in the laboratory. Finally, all Lab users require wearing protective gloves that protect the hands and should ensure the correct use.