Nucleophilic Substitution: Preparation of 1-Bromobutane and Alkyl Halide Classification Tests Introduction This procedure was undertaken in order to convert a primary alcohol, 1-butanol, into a primary alkyl halide, 1-bromobutane. This was done using hydrobromic acid. Additionally, tests were performed to assess the degree of the alkyl halide: primary, secondary or tertiary. These tests were the silver nitrate test and the sodium iodide test. The goal of these tests was to verify that 1-bromobutane, a primary alkyl halide, had in fact been formed. Data and Results 0.844 grams of product were collected. As 1-bromobutane has a molecular weight of 137.02 grams/mole, this gives 0.00616 moles of 1-bromobutane. The limiting reagent in this reaction …show more content…
In these tests, the formation of a precipitate confirms the presence of a halogen and the rate that the precipitate is formed indicates the degree of saturation of the alkyl halide. Sodium iodide reacts with alkyl halides through the SN2 mechanism. As such, the reaction occurs, and thus the precipitate forms, most quickly when reacting with primary alkyl halides. The precipitate formed in 1 minute and 20 seconds, which is indicative of a primary alkyl halide, so this test was successful and correctly identified the primary alkyl halide. Silver nitrate reacts with alkyl halides via the SN1 mechanism. As such, the reaction occurs, and thus the precipitate forms, more quickly when reacting with tertiary alkyl halides. This is because tertiary alkyl halides are better able to form carbocation transition states than primary alkyl halides because the charge can be better distributed. However, a precipitate formed in this test after only 1 minute and 5 seconds. This is a false positive and thus the test failed to distinguish between the different degrees of alkyl …show more content…
As different bonds require different amounts of energy to bend and stretch, they absorb and transmit different amounts of radiation. This data is then collected by the spectrometer and transposed into graph form. The different amounts of absorbance for various functional groups and types of bonds have been established and can be used to identify compounds. Also, an IR spectrum can be compared to known “fingerprint” spectra in order to identify the compound. When compared to the fingerprint spectrum for 1-bromobutane found in Experimental Organic Chemistry, the IR spectrum collected from the data was very similar. This indicates that the product was indeed
After 28 minutes, the mixture stopped boiling, and approximately 4.5 ml of bromobenzene was added drop by drop in the mixture, and color of the mixture was turned light brown orange. Then, the phenylmagnesium bromide was cooled in ice bath for a few minutes, and 10 ml of anhydrous diethyl ether was added in the mixture by using the syringe. After that, approximately 2.3 ml of methyl benzoate was added to the reaction, and it was added slowly slowly because the reaction was exothermic which needed to be cool in order to maintain a gentle reflux. Once all the methyl benzoate solution was added, the heating mantle was removed from the reaction flask and was cooled to the room temperature. During the reaction, a milky white salt began to precipitate, and the reaction flask was swirled for ten minutes until most of the reaction became visibly subdivided.
Cadet Eric Wiggins Date: 18 September 2014 Course Name: Chem 100 Instructor: Captain Zuniga Section: M3A Identification of a Copper Mineral Intro Minerals are elements or compounds that are created in the Earth by geological processes. The method of isolating metals in a compound mineral is normally conducted through two processes.
Our latest lab covered a detailed description of atoms and molecules, laid out in a distinctive way using balls and sticks for valence electrons and bonds. We were given charts to fill out recoding our findings regarding several molecules and their electron count, type of bonds,
Functional group tests were performed on Unknown 30A to help identify and rule out functional groups present and not present. Chemical reactions carried out in functional group tests only work with certain functional groups. In functional group tests, control compounds are important
As the name implies, the bromination mechanism in an electrophilic aromatic substitution reaction that replaces an atom on the ring with a bromine atom. The addition of the bromine is driven by the presence of a Lewis acid catalyst and a bromine atom. In most bromination mechanisms, liquid bromine is the preferred reagent to complete the reaction. However, due to potential safety concerns, the aromatic ring was brominated by using a compound of hydrobromic acid and potassium bromate in an acetic acid solution (see Figure 2 for the bromine formation).1 Liquid bromine is known for generating hazardous fumes, so this solution is significantly safer for bromine production. This formation of bromine is crucial for the bromination reaction to
In this experiment, Ba^2+ was the excess reagent for the majority of tests in all 3 stages. During the stages, the times where IO3 was the excess reagent was when there was more starting IO3 than Ba2+ and vice versa when Ba^2+ was the excess reagent. In the experiments, when the clear liquid solution was mixed with sodium sulfate, it determined whether there was excess Ba^2+ based on the color it produced. When it produced a cloudy color, it meant that there was excess barium in the mix. When excess IO3 was determined it produced a black color when there was excess IO3.
This helps to indicate whether or not the reaction follows Markovnikov’s Rule, which states that the electrophile (E+) will add to the carbon involved in a double bond that produces the most stable carbocation. If the rule is followed, the reaction will proceed according to the mechanism in Figure 1. In the silver nitrate test, the alkyl bromide is added to AgNO3. The rate of precipitation with 2° should be faster than the solution with the 1° alkyl halide. In the sodium iodide test, the alkyl halide is added to sodium iodide in acetone.
A formation of a white precipitate (AgCl) showed the presence of the chloride ion, Cl-. As the lab manual states, if a precipitate is formed, this test ultimately gives positive results for a halogen or sulfate, since silver salts are also insoluble (1). However, shown in Table 3, when mixing the unknown to find nitrate, carbonate, and sulfate, no positive results were produced. For the anion test, a white precipitate of silver chloride (AgCl) was formed when a solution of AgNO3 was added to the solution of NaCl. In this double-displacement reaction, all the states of the reactants are aqueous, which means they are dissolved in water (6).
Chem 51 LB Experiment 3 Report Scaffold: Bromination of Trans-Cinnamic Acid 1. The goal of this experiment was to perform a halogenation reaction through the addition of two bromides from pyridinium tribromide. This was accomplished by reacting trans-cinnamic acid with pyridinium tribromide. After the reaction took place, melting point analysis was conducted to find out the stereochemistry of the product, which could either be syn-addition, anti-addition, or syn + anti-addition. 2.
The purpose of this experiment is to perform a two step reductive amination using o-vanillin with p-toluidine to synthesize an imine derivative. In this experiment, 0.386 g of o-vanillin and 0.276 g of p-toluidine were mixed into an Erlenmeyer flask. The o-vanillin turned from a green powder to orange layer as it mixed with p-toludine, which was originally a white solid. Ethanol was added as a solvent for this reaction. Sodium borohydride was added in slow portion as the reducing agent, dissolving the precipitate into a yellowish lime solution.
Nevertheless, the latter is not used in this experiment since it is very reactive and extremely flammable. On the contrary, NaBH4 is relatively mild and it can be used with protic solvents. In this manner, 1.507 grs of the ketone 9-fluorenone were mixed with 30.0 ml of 95% ethanol in a 125 ml Erlenmeyer flask. The bright yellow mixture was stirred during 7 minutes until all the components were dissolved.
The objective of this experiment was to use an aldol condensation reaction to synthesize 3-nitrochalcone from 3- nitrobenzaldehyde. This was accomplished with a Diels-Alder reaction that utilized 3-nitrobenzaldehyde, acetophenone, ethanol, and sodium hydroxide. The mechanism for the synthesis of 3-nitrochalcone is presented in Figures 1 and 2. The alpha carbon on the acetophenone is deprotonated. This is followed by the attack of the alpha carbon anion on the carbonyl carbon on the 3-nitrobenzaldehyde.
The N‟-2- (bromophenyl)-N,N-dimethylurea 16 underwent lithiation on the nitrogen to form a monolithio intermediate using MeLi, followed by bromine-lithium exchange using t-BuLi to give the dilithio species 17. 14 The intermediate 17 was then exposed to carbon monoxide to give 18, which after cyclization forms the intermediate 19, followed by loss of LiNMe2 to give 20, and finally after work up with dilute acid yielded the isatin product 1. 1 13 14 15 6 N O O 1) MeLi, 0 C CO Br N H O NMe2 2) t-BuLi, 0 C Li N O NMe2 Li C N Li
Experiment 2 Report Scaffold (Substitution Reactions, Purification, and Identification) Purpose/Introduction 1. A Sn2 reaction was conducted; this involved benzyl bromide, sodium hydroxide, an unknown compound and ethanol through reflux technique, mel-temp recordings, recrystallization, and analysis of TLC plates. 2. There was one unknown compound in the reaction that was later discovered after a series of techniques described above.
Distillation and IR Spectroscopy CHE 361L Christian Johnson 02/17/2018 Introduction The purpose of this lab was to separate an unknown binary mixture by distillation and use IR spectroscopy along with the placement of known functional groups in order to determine the identity of the compounds. Based upon the potential unknown solutions, there are a few specific functional groups that can specifically be targeted in order to accurately depict the identity. The functional groups and specified area on the IR spectrum are located below.