The purpose and goal of this experiment is to use the knowledge of substitution reactions and laboratory techniques to synthesize (2-bromoethyl) benzene from 2-phenylethanol; furthermore, to determination if the synthesis is successful, the methods of thin layer chromatography (TLC), the theorized use of gas chromatography along with a mass spectrometer (GC-MS) and flame ionization detector (GC-FID), as well as infrared (IR) spectroscopy will all have their application in this experiment. The hypothesis of this experiment is that if the synthesis is done correctly and is successful, on the TLC, the expected synthesized (2-bromoethyl) benzene in lane 1 should match that of the standard (2-bromoethyl) benzene in lane 2 but may also contain some impurities, somewhat …show more content…
The solution is then stirred with a glass rod and put to cool in an ice-water bath before the slow addition of 1.0 mL of concentrated sulfuric acid (H2SO4) into the cold mixture in order to prevent the transpiration of undesired side reactions. In a separate test tube, 1-2 mL of 3 M aqueous sodium hydroxide solution can also be placed in the ice bath for extraction later on. After the mixture of NaBr, H2SO4 and 2-phenylethanol has been cooled and mixed, a solid will form. At this point, the application of the method of reflux can commence in order to both increase the reaction rate and to prevent any liquids from being evaporated, due to constant application of heat. With the apparatus set up (in addition to making sure all joints are well sealed, excluding the condenser top), the vial can then be put out of the ice bath, and put to warm. With stirring, all of the solid will eventually dissolve, and with constant heating, the mixture will gently reflux at around 160 ºC (using thermometer in the metal block to confirm), where the biphasic reaction mixture can then vigorously be stirred (with certain
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.
The product that is formed the most is 1-methyl-1-cyclohexexene because it is the most highly substituted and thus the most stable, while 3-methyl-1-cyclohexene and methylenecyclohexane are produced less because they are less highly substituted and thus less stable. This reaction proceeded through an E1 pathway. In the mechanism the sulfuric acid provides a proton which protonates the hydroxyl group on the 2-methylcyclohexanol. This forms a good leaving group on the 2-methylcyclohexanol which leaves the compound as water. A carbocation results and H2PO4^- deprotonates a hydrogen on a carbon atom next to carbon atom with a positive charge resulting in alkenes with the major and minor products. One major technique used in this experiment was distillation. The reason distillation works is because different organic compounds have different boiling points. Usually a mixture containing two compounds is placed in the round bottom flask in the distillation apparatus. When the distillation apparatus is turned on and heat is applied, the vaporization of the compound in the mixture with the lower boiling point occurs. This compound, then condenses in the condenser and is received by the receiving flask at the end of the distillation
7. Using the stirring wire, stir the mixture until the solute completely dissolves. Turn the heat source off, and allow the solution to cool.
“Benzene is the simplest aromatic compound.” As an excellent solvent, it can produce a variety of derivatives with minimal reagents. Its characteristic bonding, unconventional by regular electron bonding, makes it extremely volatile. As a result, its use is banned outside of laboratory and industry use. Toluene is described as “identical to benzene except that one of the hydrogen atoms has been replaced by a methyl group.
From the lab book (1), Experiment 12.2A discusses the nitration of methyl benzoate to give an example of an electrophilic aromatic substitution reaction. This is seen in this experiment as a hydrogen on methyl benzoate is replaced with a nitronium ion. To achieve this an acid-base reaction, sulfuric acid and nitric acid react to produce a nitronium ion, a hydronium ion, and 2 bisulfate ions as seen in Structure 1. The nitronium ion reacts with an aromatic ring forming a sigma complex, Structure 2; which further stabilizes generating an aromatic ring due to conjugation, Structure 3. The formation of an intermediate is not mandatory, however it appears to be an easier resonance stabilizing mechanism (2). The final products of this
In acid-base titration solution without a known molarity is placed in an Erlenmeyer after it’s volume is measured. An indicator is added to the solution most of the time it is phenolphthalein. The solution with a known concentration is placed in burette with a tap in the end. By opening the tap slightly solution in the burette is poured in to the solution in Erlenmeyer drop by drop. After a while the solution in Erlenmeyer forms a color change. This is the turning point for the solution. At the turning point by the volume consumed in burette the molarity of the other solution can be
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...
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 goal of this experiment is to determine which products are formed from elimination reactions that occur in the dehydration of an alcohol under acidic and basic conditions. The process utilized is the acid-catalyzed dehydration of a secondary and primary alcohol, 1-butanol and 2-butanol, and the base-induced dehydrobromination of a secondary and primary bromide, 1-bromobutane and 2-bromobutane. The different products formed form each of these reactions will be analyzed using gas chromatography, which helps understand stereochemistry and regioselectivity of each product formed.
For this experiment we have to use physical methods to separate the reaction mixture from the liquid. The physical methods that were used are filtration and evaporation. Filtration is the separation of a solid from a liquid by passing the liquid through a porous material, such as filter paper. Evaporation is when you place the residue and the damp filter paper into a drying oven to draw moisture from it by heating it and leaving only the dry solid portion behind (Lab Guide pg. 33.).
Once the mixture had been completely dissolved, the solution was transferred to a separatory funnel. The solution was then extracted twice using 5.0 mL of 1 M
Saturated sodium chloride solution, also known as brine solution, is used to wash the distillate mixture. The distillate mixture is the phosphoric acid the co-distilled with the product. The brine solution also removes most of the water from the 4-methylcyclohexane layer. When six drops of 4-methylcyclohexene were added with two
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.
The catalytic process occurs at lower temperature anf offers higher selectivity but requires frequent regeneration of the catalyst. Then, the products are cooled and introduced into a pair of separators which separate the unreacted hydrogen. The unreacted hydrogen is compressed and recycle back to the feed and reactor. The products that leaving the separators are heated before introduced into a distillation column which the toluene is separated from the stream and recycle back to the...
In this experiment the Sodium Hydroxide solution went through three different phases where its quality and quantity changed. The first phase was called I. Preparing Approximately 0.1M NaOH, 1000mL of clear distilled water was boiled and then chilled to room temp.