Figure 4: Reaction 4 [1-bromopentane + K+ -OC(CH3)3 (Potassium tert-butoxide)] and its (theorized) major and minor products are shown. The major product was 1-t-butoxypentane and the minor was 1-pentene (in consecutive order). Note that 1-pentene increases in reaction 4 relative to reaction 3. This is due to steric hindrance (bulky tert-butoxide) which decreases the SN2 product in reaction 4 relative to reaction 3. Experimental Method A 25 ml RB flask was set-up up for reflux with a drying tube and 1 ml of 1.5 M of potassium tert-butoxide was added along with 8 drops of 1-bromopentane. This was then heated to 80 °C - 90 °C for an hour. When the mixture cooled, 10 ml of methyl-t-butyl ether was added to the flask. This was extracted and
Objective: The objective of this lab is to observe the synthesis of 1-bromobutane in an SN2 reaction, to see how a primary alky halide reacts with an alcohol.
group. The location of this hydroxyl functional group will impact the molecular structure of the
A 0.5 g of sodium tungstate dihydrate was weighed and transferred into a 50-mL round-bottom flask with a magnetic stir bar. Approximately 0.6mL of Aliquat 336 was then transferred carefully into the round bottom flask using a 1mL syringe. The round bottom flask and its contents were then set up in an oil bath. 11mL of 30% hydrogen peroxide and 0.37 g of potassium bisulphate were added to the reaction mixture in the round bottom flask and stirred using a magnetic stirrer. Lastly, 2.5mL of cyclohexene was added using automatic dispenser and the mixture stirred. A condenser was fitted on the round bottom flask, clamped and attached to water horses. The reaction mixture was then heated on the oil bath and the reflux process initiated for an hour while stirring the mixture vigorously. Half way while rinsing, any trapped cyclohexene in the condenser was rinsed. After 1 hour, the round bottom flask was rinsed
Abstract: One mixture of two unknown liquid compounds and one mixture of two unknown solid compounds were separated, isolated, purified, and characterized by boiling point. Two liquid unknowns were separated, isolated, and purified via simple distillation. Then, the process of an acid-base extraction and washing were used to separate two unknown compounds into two crude compounds: an organic acid and a neutral organic compound. Each crude compound was purified by recrystallization, resulting in a carboxylic acid (RCO2H) and a pure organic compound (RZ). The resulting mass of the pure carboxylic acid was 1.688g with a percent recovery of 31.80%, the boiling range was 244-245 °C, and its density was 2.0879g/mL. The resulting mass of the pure organic solid was 2.4902g with a percent recovery of 46.91%, the boiling range was 52.0-53.4°C, and its density was 1.5956 g/mL.
The objective of this laboratory experiment is to study both SN1 and SN2 reactions. The first part of the lab focuses on synthesizing 1-bromobutane from 1-butanol by using an SN2 mechanism. The obtained product will then be analyzed using infrared spectroscopy and refractive index. The second part of the lab concentrates on how different factors influence the rate of SN1 reactions. The factors that will be examined are the leaving group, Br versus Cl-; the structure of the alkyl group, 3◦ versus 2◦; and the polarity of the solvent, 40 percent 2-propanol versus 60 percent 2-propanol.
Purpose: The purpose of this experiment is to observe a variety of chemical reactions and to identify patterns in the conversion of reactants into products.
With a 9-inch pipet was used to add water through the condenser to keep the flask no more than half way full. Clove oil was extracted from the distillate in 1 mL increments every 5 to 10 minutes. The distillation and extraction process was approximately 37 minutes with 7 mL of distillate recovered. The product recovered was a light yellow liquid color with the same strong, sweet, cinnamon odor as the raw clove. 1 mL of dichloromethane solution was used to rinse the Hickman still and was then transferred to the centrifuge tube. Another 2 mL more of dichloromethane was added and shaken vigorously. Upon shaking the the mixture turned a cloudy white color with two layers resulting. The major component of clove oil was extracted with two more 3 mL portions of dichloromethane solution. The mixture was allowed to cool and left in the hood overnight to dry.
The solvolysis of t-butyl bromide is an SN1 reaction, or a first order nucleophilic substitution reaction. An SN1 reaction involves a nucleophilic attack on an electrophilic substrate. The reaction is SN1 because there is steric obstruction on the electrophile, bromine is a good leaving group due to its large size and low electronegativity, a stable tertiary carbocation is formed, and a weak nucleophile is formed. Since a strong acid, HBr, is formed as a byproduct of this reaction, SN1 dominates over E1. The first step in an SN1 reaction is the formation of a highly reactive carbocation, in which a leaving group is ejected. The ionization to form a carbocation is the rate limiting step of an SN1 reaction, as it is highly endothermic and has a large activation energy. The subsequent nucleophilic attack by solvent and deprotonation is fast and does not contribute to the rate law for the reaction. The Hammond Postulate predicts that the transition state for any process is most similar to the higher energy species, and is more affected by changes to the free energy of the higher energy species. Thus, the reaction rate for the solvolysis of t-butyl bromide is unimolecular and entirely dependent on the initial concentration of t-butyl bromide.
The initial product is the beta-hydroxyketone, which rapidly undergoes dehydration and creates the final product, trans-p-anisalacetophenone. Technically, both the carbonyls cannot be mixed together with sodium hydroxide to get one product. We will get a dominant product of trans-p-anisalacetophenone. This reaction is an exception and we get away with it. P-anisaldehyde and acetophenone together only make one enolate. This helps our exception, but there are still two carbonyls. With our weak base, we should be worried about acetophenone reacting with itself but we are not. This is due to steric hindrance, like I stated earlier. Aldehydes are better electrophilic carbons and therefore the ketone will react with the aldehyde faster than reacting with itself. It will quickly form the product trans-p-anisalacetophenone because it is the favored product. We do not have to use expensive LDA, we can use the weaker base and get away with it.
After the initial mixture has refluxed, 9.11 grams of benzophenone was dissolved in 100 mL of anhydrous ether in a beaker and was then transferred into the separatory on the reflux apparatus. This solution was then added to the Grignard reagent at a drop wise rate while stirring. After the benzophenone was added, the mixture was then refluxed for 15 minutes on a heating mantle.
Determining how a mechanism comes to be is crucial as a scientist and arriving to conclusions is a crucial component which lead to examining and determining which mechanism takes place when two or more substrates are made to react. At the end of the experiment a mechanism was determined based on the purified product’s melting point. This was accomplished by having the reaction take place but also through acquiring the melting point and comparing the number to the melting point which was already established by the scientific community. (Q1) When 0.252 g of trans-cinnamic acid was mixed in 2.5 mL glacial acetic acid and 0.434g pyridinium tribromide was added, the resulting product reflects an addition reaction. In general, reactions take place to achieve its lowest Gibb’s free energy because it’s at
The purpose of this lab is to understand the process of eliminating an alkyl halide to form an alkene. The experiment is carried out by first converting the alcohol, 2-methy-2-butanol, into the alkyl halide of 2-chloro-2-methylbutane that will then be put through dehydrohalogenation that favors elimination reaction (E2) to create a mixture of 2-methyl-2-butene and 2-methyl-1-butene. A fractional distillation will be taken to purify the mixture and an additional gas chromatography will be done to further analyze the mixture composition. A bromide test will be done to determine the product of an alkene in the experiment.
Bromine is a naturally occurring element that is a liquid at room temperature. In it has a brownish-red color with a bleach-like odor and it dissolve in water. An found in bromine is a naturally in the earth’s crust and in seawater in various chemical form. Can also be found as an alternative to chlorine in swimming pool. Then some product containing bromine are used in agriculture and sanitation as an fire retardants.
In this experiment were used three separation techniques: extraction, sublimation and recrystallization. During the first method, 0.70 g sample of salicylic acid-naphthalene mixture was dissolved in 10 ml of diethyl ether. The solution was placed in a separatory funnel and 10 ml of saturated aqueous sodium bicarbonate solution was added to it. After the initial gas was
Bromhexine is an expectorant [2,3]. It works by increasing mucus secretion and the volume of the sputum which is leading to a reduction of mucus viscosity [2,3]. Therefore, it aids in expectorating the phlegm