Electrophilic Aromatic Substitution And Column Chromatography Lab Report

The mixture was transferred to an ice bath to crystallize the product, after which the product was collected by vacuum filtration on a Hirsch funnel, washing the flask with small aliquots of cold xylene and pouring the solution over the crystals, allowing the vacuum to thoroughly dry the product. Additional drying was achieved by transferring the product to filter paper and pressing the crystals to remove any excess moisture. The product was then weighed and a melting point determined. A comparative TLC was run in Hexanes:Ethyl Acetate solvent against maleic anhydride to verify the purity of the

Experimental Method: A filtration apparatus was set up. Solid iron(III) chloride hexahydrate was dissolved in water. In a separate container, sodium acetate trihydrate (NaC2H3O2 x 3 H2O) was also dissolved in water. Sodium acetate trihydrate was then added to iron(III) chloride. 2, 4-pentanedione (C5H8O2) was dissolved in methanol; it was then added to the iron(III) chloride/sodium acetate solution. The product of this mixture was filtered, and the precipitate

The red pigmented compounds extracted via column chromatography and LC-Diol cartridges were further separated and characterized via GC-MS. The chromatograms are seen in Figures 2 and 4 respectively. As seen by Tables 1 and 3, LC-Diol purified MI-1 sample contained more impurities than the sample purified by

In Part 1, 50 milliliters of 5% sodium hydroxide solution was obtained and observed in a 100 mL beaker and 30 milliliters of pH 2 dissolved iron solution was also obtained and observed in a 50 mL beaker. To observe the behavior of dissolved iron with sodium hydroxide, 5 milliliters of pH 2 dissolved iron was transferred to a large test tube. Drops of 5% solution of sodium hydroxide were slowly added and monitored for physical changes. A glass stir rod was used to transfer a small amount of solution onto pH paper in between drops of 5% solution of sodium hydroxide until the solution had a pH of 8.

In electrophilic aromatic substitution, an atom that is attached to an aromatic compound is replaced by an electrophile. The stability of aromatic rings makes the need for a very strong electrophile for the molecule to be formed. Nitro-groups and halogens are good examples of the kind of electrophiles that should be used. The rate of the reaction and direction are affected by the electrophile. A carbocation intermediate is formed when the electrophile attacks one of the double bonds on the molecule and breaks it. The double bond can be reformed by a nucleophile that attacks it as a base. As stated, a very strong electrophilic ion is needed to change the stability of the aromatic ring. In the case of two electrophiles, the stronger one should be used to create the strong cation which can then break the double bond.

The initial goal of this experiment was to investigate the properties of an unknown acid or base. These properties include pH, concentration, and how the solution behaves once titrated. In order to accomplish these goals, the initial pH of the unknown compound needed to be found through the use of pH strips and/or a PASCO probe. It was also necessary to titrate the unknown compound to find the equivalence point, which would allow the calculation of the initial concentration of the unknown chemicals. In order to see how dilution affected the pH of the unknown compound, it was necessary to dilute the unknown compounds over a series of steps and observe the trend. Finally, it was helpful to test the household chemicals for their acidic or basic properties and compare how they reacted to the reactions of the unknown compounds.

A total of 2-mL of glacial acetic acid was added to the vial. Three drops of concentrated H2SO4 and a boiling chip were added to the vial. The vial was attached to a clamp and rested in a sand bath that ranged between 150-160°C. A cold, damp kim wipe was placed around the tip of the vial to act as a condenser. The mixture was refluxed for one hour. Once the hour passed, the reaction mixture was cooled to room temperature and the sand bath was turned off. After the boiling chip was removed from the vial, 1-mL of 5% sodium hydrogen carbonate (NaHCO3) was slowly added to the reaction mixture, capped and swirled. The vial was shaken to mix the contents and the cap was removed to release the pressure. This was repeated until the bubbles were no longer produced. A Pasteur pipet was used to remove the aqueous layer which was disposed in a test tube labeled “Aqueous Layer”. The extraction of the upper organic layer was repeated two more times with new 1-mL portions of 5% NaHCO3, placing the aqueous layer in the labeled test tube each

An electrophilic aromatic substitution reaction occurs when a hydrogen atom from an aromatic ring is replaced with an electrophile. This reaction is of the SN2 type and is a two-step mechanism. The first step is the rate-determining step, where the electrophile forms a sigma-bond to the benzene ring, creating a positively charged intermediate.1 In the second step, the hydrogen atom is removed, resulting in a substituted benzene ring. When a mono-substituted benzene goes through an electrophilic aromatic substitution reaction, there are usually three possible products that can be formed; ortho, para, meta.1 These different products occur because during an electrophilic substitution reaction, certain positions on benzene react faster than the

When observing the thin-layer chromatography, it was evident that two compounds from experiment 5 expressed no impurities. There was one yellow band from the ferrocene dot, one red band from the acetylferrocene dot, and two yellow and red bands from the standard consisting of both

In the proposed method, the sample solution is dissolved in acetonitrile with (1 mg/mL of an analog of fentanyl (CH2CH2CH2) as an internal standard) so that the sample solution is at a concentration of 0.1mg/mL. 1mL of the acetonitrile solution is placed into a centrifuge with 50mg of 4-DMAP (4-(dimethylamino)-pyridine) and 50microL of HFBA (heptafluorobutyric anhydride). The solution is allowed to react for 1h at 75C, following which 5 mL of isooctane and 1N of aqueous sodium carbonate are added, and then centrifuged. 1 mL of this layer is then diluted using 10 mL isooctane. 5 mL of this dilution is placed in a centrifuge tube and back extracted using 5mL of 1 N sulfuric acid. The solution is then ready to be chromatographed. If the sample solution is adulterated with sugars, prior to dissolving the solution in acetonitrile, dissolve an amount equivalent to .1 mg of fentanyl in

The apparatus was set-up in fume hood. After adding 5ml of acetic anhydride and five drops of 85% phosphoric acid into 50ml Erlenmeyer flask which contained 2.001g salicylic acid, the flask was heated on a hot plate (75℃ ) for 15 minutes while stirring the flask’s content. A butcher funnel was then set-up for filtration of the flask’s content.

900ml THF and 0.973moles of Potassium tertiary butoxide, was charged into 5L RB under N2 atm and stirred for 5min 0.936moles of Wittig salt was charged into the above cooled reaction mixture, colour of the reaction mixture changes to yellow. 0.749moles of acetophenone was charged using a dropping funnel and stirred at 30-40○C. TLC checked, it complies, reaction was cooled. Hexane and water charged into it and stirred for 30min at 5-8°C. The reaction mass organic layer was separated followed by its washing with hexane, water and brine, it was filtered under vacuum.

The previous wash and collection of fractions was done again using the elution buffer. All 10 fractions collected were analyzed using UV spectra at 280 nm using the *** as the blank.

Without letting the column run dry, hexane:acetone (1:1) was introduced into the column, and in the same manner the eluates were collected. This was the same for the succeeding eluents, and went on until no more colored eluates could be obtained from the column.

This experiment involves the separation and identification of 2 organic compounds (1 Neutral Compound and 1 Acidic Compound) in a mixture. Separation techniques used in this experiment include solvent extraction, simple distillation and recrystallization using a suitable solvent determined through a solubility test. The identification method used was through Melting Point Determination. By obtaining data of the melting points of the 2 purified compounds and cross-referencing from a list of possible organic compounds, the 2 organic compounds were