Relative Reactivity of Anilines Abstract: Various Anilines were tested with Br2/HBr solution, the products were crystallized and melting points attained to verify relative reactivity. My assignment, 2,4-Dibromoanisol, was prepared in a yield of 52% with a melting point of 55-58 C . Reaction: Mechanism: Procedure: Anisole (0.35mL, 0.0378mol) was obtained and placed in a pre-weighed 25 mL round bottom flask, along with 2.5 mL of glacial acetic acid and a magnetic stir bar. Then the reaction apparatus was assembled, the dry tube was charged with conc. sodium bi sulfate, the 25 mL round bottom was attached to the apparatus, and 5 mL of Br2/HBr mixture was obtained and placed in the round bottom. The reaction took place for 20 minutes. An orange liquid was obtained and placed in a 125 mL Erlenmeyer flask along with 25 mL of water and 2.5 mL of conc. Sodium bisulfate soln. The solution was then placed in an ice bath to precipitate and then the solid product was filter in a Buchner funnel. These crystals were then re-dissolved minimum amount of hot solvent (heptane) and recrystallized. Once a dry product was obtained, a melting point was established (2,4-Dibromoanisol mp 55-58 C) and percent yield was established (52%). Results: Through a melting point reading, it was determined that the product obtained was 2,4-Dibromoanisol mp 55-58 C. The products obtained by my partners, were determined to be: (p-bromoacetanilide mp 160-165 C) and (2,4,6 tribromoaniline, mp of 108-110 C) respectively. Discussion and Conclusions: Interpreting these results have concluded that relative reactivity of these three anilines in order of most reactive to least reactive go; Aniline > Anisole > Acetanilide. Aniline, has an NH2 , the most active substituent , and adds to any ortho/para position available on the ring. This data is confirmed with the product obtained, (2,4,6 tribromoaniline, mp of 108-110 C). As for anisole, it has a strongly activating group attached, OMe an alkoxy group, and it added in two of the three available spots, both ortho. The results conclude: (2,4-Dibromoanisol mp 55-58 C ). Acetanilide has a strong activating group attached, acylamino group, but this group is large and the ortho positions are somewhat hindered so the majority of the product obtained added at the para position, results conclude: (p-bromoacetanilide mp 160-165 C). Since all the substituents attached to the aromatic rings were activators the only products able to be obtained were ortho/para products.
The goal of this two week lab was to examine the stereochemistry of the oxidation-reduction interconversion of 4-tert-butylcyclohexanol and 4-tert-butylcyclohexanone. The purpose of first week was to explore the oxidation of an alcohol to a ketone and see how the reduction of the ketone will affect the stereoselectivity. The purpose of first week is to oxidize the alcohol, 4-tert-butylcyclohexanol, to ketone just so that it can be reduced back into the alcohol to see how OH will react. The purpose of second week was to reduce 4-tert-butylcyclohexanol from first week and determine the effect of the product's diastereoselectivity by performing reduction procedures using sodium borohydride The chemicals for this lab are sodium hypochlorite, 4-tert-butylcyclohexanone
During our investigation we first decided how much sodium bicarbonate we would be using. We decided on 11 grams which was about half of the crucible. We then used the bunsen burner to heat up the sodium bicarbonate. We heated the sodium bicarbonate expecting there to would be a chemical reaction and the atoms would be rearranged during thermal decomposition. We heated the sodium
First, A (3.348 g, 0.031 mol) and triethylamine (6.060 g, 0.060 mol) were added to a glass flask. Then, B (5.850 g, 0.030 mol) was added dropwise to the resulting reaction mixture over a period of 2 h, and the temperature was maintained at 5 °C. The reaction mixtures were carefully maintained at 80 °C for another 5 h. Finally, the reaction mixture was washed with diethyl ether, separated by reduced pressure suction filtration, and dried in a vacuum oven at 100 °C for 12 h to afford a white solid powder, namely, poly-N-aniline-phenyl phosphamide (PDPPD) in 93%
Bibliography "Sodium Bicarbonate" American Heritage Dictionary and Electronic Thesaurus (1985) 21: 347 "Acids and Bases" Science Activities Winter 95, Vol. 31 issue 4, p28. McCarthy, E. Jerome Basic Chemistry Homewood Illinois: Irwin-Dorsey, 1968.
Discussion The reaction of (-)-α-phellandrene, 1, and maleic anhydride, 2, gave a Diels-Alder adduct, 4,7-ethanoisobenzofuran-1,3-dione, 3a,4,7,7a-tetrahydro-5-methyl-8-(1-methylethyl), 3, this reaction gave white crystals in a yield of 2.64 g (37.56%). Both hydrogen and carbon NMR as well as NOESY, COSY and HSQC spectrum were used to prove that 3 had formed. These spectroscopic techniques also aided in the identification of whether the process was attack via the top of bottom face, as well as if this reaction was via the endo or exo process. These possible attacks give rise to four possible products, however, in reality due to steric interactions and electronics only one product is formed.
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.
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.
When 1-bromobutane is reacted with potassium t-butoxide there is only one product formed, 1-butene. This is because the halide is on a primary carbon thus producing only one product.
Then the reaction tube was capped but not tightly. The tube then was placed in a sand bath reflux to heat it until a brown color was formed. Then the tube was taken out of the sand bath and allowed to cool to room temperature. Then the tube was shaken until a formation of a white solid at the bottom of the tube. After formation of the white solid, diphenyl ether (2 mL) was added to the solution and heated until the white solid was completely dissolved in the solution. After heating, the tube was cooled to room temperature. Then toluene (2 mL) was added to the solution. The tube was then placed in an ice bath. Then the solution was filtered via vacuum filtration, and there was a formation of a white solid. Then the product was dried and weighed. The Final product was hexaphenylbenzene (0.094 g, 0.176 mmol,
Enantiomers, a type of isomer, are non-superimposable, mirror images of each other. Diasteriomers, another type of isomer, are non-superimposable, non-mirror images of each other. Dimethyl maleate and dimethyl fumarate are diasteriomers, as they are not mirror images but instead vary in the orientation of the carbomethoxy groups around the double bond. Dimethyl maleate is the cis-isomer because both groups are on the same side and dimethyl fumarate is the trans-isomer because the two groups are on opposite sides. A bromine free radical mechanism was required for this conversion. First, energy from light is required to create two bromine free radicals from Br2. Then one of the free radicals attacks the double bond in dimethyl maleate, breaking it and creating a carbon radical on the other carbon. The bond then rotates and reforms, freeing the bromine radical and creating the trans-isomer, dimethyl fumarate. Bromine in this reaction is acting as a catalyst in this reaction and then cyclohexane is added at the end to neutralize the bromine free radicals. The activation reaction of the radical reaction is lower than the activation energy of the addition reaction, which is why it occurred more quickly. This reaction was successful because the percent yield was 67.1%, which is greater that 65%. It also demonstrated the expected principles, as the reaction did not occur without the presence of both light and bromine. The dimethyl fumarate had a measured boiling point of 100C to 103C, which is extremely close to the expected boiling point of 102C to
Through an oxidation-reduction reaction sequence, Borneol is converted to isoborneol. First, borneol is oxidized through a reaction with sodium hypochlorite at 400C to form camphor. When the camphor is then reduced by sodium borohydride, isoborneol is formed. The percent yeild of isoborneol collected was 56.4%, and the melting point range was found to be between 174.2-179.90C. Through analysis of the product through 1H NMR spectroscopy the percent purity is found to be 77.2% pure isoborneol.
Thickett, Geoffrey. Chemistry 2: HSC course. N/A ed. Vol. 1. Milton: John Wiley & Sons Australia, 2006. 94-108. 1 vols. Print.
The experiment achieved its purpose in that the concentration of Ba(OH)2 solution was determined. According to the conductometric titration, the concentration of Ba(OH)2 (aq) was 0.196 M. Calculations based on gravimetric analysis revealed a concentration of 0.0669 M. Evidently, there is a high degree of imprecision between the values determined by each technique. It appears however that the gravimetric analysis was more accurate. The standard deviation for BaSO4 mass was 0.035 and
A mixture of 2 mL aniline, 15 mL deionized water and 3 mL acetic anhydride were stirred. After thirty minutes the reaction was complete and the product was completely precipitated out of the solution. Vacuum filtration was used to isolate the crude acetanilide using a 125 mL filter flask and porcelain Büchner funnel. The product was then washed with 2 mL of ice water and left to dry for about twenty minutes. The observed melting point for the crude acetanilide was 114.3 °C - 115.7 °C. The second procedure dealt with finding a suitable solvent to recrystallize the crude acetanilide. A sand bath was set up and 0.5 mL of each solvent was added to 50 mg of acetanilide in four different test tubes. The four solvents used to test the solubility of the acetanilide were water, ethanol, dichloromethane and hexanes. If the solid dissolved in the solvent at room temperature then it was too soluble and that solvent could be eliminated. The acetanilide completely dissolved in ethanol and dichloromethane, therefore eliminating them from being the suitable solvent. If the solid did not dissolve in room temperature then it was placed in the sand bath and left to boil. If the solid dissolved, it was placed in the ice bath and if crystals were observed coming out of the solution then the suitable solvent was found. The suitable solvent was water as the crystals came out once placed in the ice bath. The
Tollen's reagent (Ammoniacal AgNO3) 4. Benedict's solution 5. Iodine solution 6. Chloroform (CHCl3) 7.