Experiment 8.2: Nucleophilic Aliphatic Substitution: Synthesis of 1-Bromobutane Reference: Schoffstall, Allen M., Barbara A. Gaddis, and Melvin L. Druelinger. "Experiment 8.2." Microscale and Miniscale Organic Chemistry Laboratory Experiments. New York: McGraw-Hill Higher Education, 2004. 267-70. Print. General Procedure: This experiment was designed to convert 1-butanol to 1-bromobutane by reacting with sulfuric acid and sodium bromide. Protonation of 1-butanol by hydrogen bromide and bromide ions on the alcohol group gave 1-bromobutane. Reflux, purification, and filtering were used to separate out the 1-bromobutane for testing using an GC spectrum and refractive index. Synthesis of 1-Bromobutane The compound was synthesized according to Experiment 8.2 from the Microscale and Miniscale Organic Chemistry …show more content…
This was allowed to mix for a few minutes; a little excess water was used to ensure that sodium bromide was fully dissolved. This mixture was placed in an ice bath while continuing to stir. 1.3 ml (24.39 mmols) of concentrated sulfuric acid was added dropwise. The flask was removed from the ice bath and heated to reflux for 1 hour while continuing to stir. The resulting top layer was transferred to a conical vial in which 1.5 mL (22.51 mmols) of 80 % sulfuric acid was added. 2.0 mL of water was added to allow a layer to form. The bottom layer was removed and transferred to another conical vial in which 2.0 mL of saturated sodium bicarbonate was added. The bottom, organic layer, was transferred to a conical vial. Calcium chloride, a drying agent, was used to collect the remaining aqueous layer that
Each subsequent trial will use one gram more. 2.Put baking soda into reaction vessel. 3.Measure 40 mL vinegar. 4.Completely fill 1000 mL graduated cylinder with water.
The primary goal of this laboratory project was to identify an unknown compound and determine its chemical and physical properties. First the appearance, odor, solubility, and conductivity of the compound were observed and measured so that they could be compared to those of known compounds. Then the cation present in the compound was identified using the flame test. The identity of the anion present in the compound was deduced through a series of chemical tests (Cooper, 2009).
The complete experimental procedure is available in the General Chemistry Laboratory Manual for CSU Bakersfield, CHEM 213, pages 20-22, 24-25. Experimental data are recorded on the attached data pages.
Triphenylmethyl Bromide. A 400 mL beaker was filled with hot water from the tap. Acetic acid (4 mL) and solid triphenylmethanol (0.199 g, 0.764 mmol) were added to a reaction tube, with 33% hydrobromic acid solution (0.6 mL) being added dropwise via syringe. The compound in the tube then took on a light yellow color. The tube was then placed in the beaker and heated for 5 minutes. After the allotted time, the tube was removed from the hot water bath and allowed to cool to room temperature. In the meantime, an ice bath was made utilizing the 600 mL plastic beaker, which the tube was then placed in for 10 minutes. The compound was then vacuum filtered with the crystals rinsed with water and a small amount of hexane. The crude product was then weighed and recrystallized with hexane to form fine white crystals, which was triphenylmethyl bromide (0.105 g, 0.325 mmol, 42.5%). A Beilstein test was conducted, and the crystals produced a green to greenish-blue flame.
A weak peak was at a position between 1600-1620 cm-1 can also be seem in the IR, which was likely to be aromatic C=C functional group that was from two benzene rings attached to alkynes. On the other hand, the IR spectrum of the experimental diphenylacetylene resulted in 4 peaks. The first peak was strong and broad at the position of 3359.26 cm-1, which was most likely to be OH bond. The OH bond appeared in the spectrum because of the residue left from ethanol that was used to clean the product at the end of recrystallization process. It might also be from the water that was trapped in the crystal since the solution was put in ice bath during the recrystallization process. The second peak was weak, but sharp. It was at the position of 3062.93 cm-1, which indicated that C-H (sp2) was presence in the compound. The group was likely from the C-H bonds in the benzene ring attached to the alkyne. The remaining peaks were weak and at positions of 1637.48 and 1599.15 cm-1, respectively. This showed that the compound had aromatic C=C function groups, which was from the benzene rings. Overall, by looking at the functional groups presented in the compound, one can assume that the compound consisted of diphenylacetelene and ethanol or
Since, the expected weight was 50.63 mg the percent yield is 59.3%. A TLC was conducted on this final product and a faint spot of 4-tert-butylcyclohexanone still appeared in lane 3 of the plate; meaning the reaction did not fully go to completion. The Rf values were 0.444, 0.156, and 0.111, where the lowest value is the trans isomer and the highest value is the ketone. This affected the IR spectrum conducted by having a carbonyl group peak at 1715 cm-1 which should not be present if all the product was 4-tert-butylcyclohexanol. However, the IR spectrum still showed peaks at 3292 cm-1 (hydroxyl group), 2939 cm-1 (sp2 carbon bonded to hydrogen) and 2859 cm-1 (sp3 carbon bonded to hydrogen) which support the presence of the alcohol. The accepted melting point of 4-tert-butylcyclohexanol is in the range of 62 – 70˙C (Lab Manual). The two melting point measurements using the Mel-Temp® machine gave ranges of 57 – 61˙C and 58 – 62˙C, which is not exact due to some 4-tert-butylcyclohexanone being present that has a low melting point of around 47 – 50˙C
W. A. Konig, D. H. Hochmuth, D. Joulain, Library of MassFinder 2.1 University of Hamburg, Institute of Organic Chemistry, Hamburg 2001
Add 138 mg of salicylic acid, a drop of 85 % phosphoric acid, 0.3 mL of acetic anhydride and a boiling chip into a reaction tube.Mix them thoroughly, and place in a steam bath for approximately 5 minutes. After the reaction tube rested in the steam bath for 5 minutes, 0.2 mL of water was added to the tube. The tube was then placed in a test tube rack to cool down to room temperture. Once the substance reached room tempertaure it was placed inside of an icebath for 10 minutes to crystallize. The product then had to undergo the filteration process. The filtered product was
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.
In a small reaction tube, the tetraphenylcyclopentadienone (0.110 g, 0.28 mmol) was added into the dimethyl acetylene dicarboxylate (0.1 mL) and nitrobenzene (1 mL) along with a boiling stick. The color of the mixed solution was purple. The solution was then heated to reflux until it turned into a tan color. After the color change has occurred, ethanol (3 mL) was stirred into the small reaction tube. After that, the small reaction tube was placed in an ice bath until the solid was formed at the bottom of the tube. Then, the solution with the precipitate was filtered through vacuum filtration and washed with ethanol. The precipitate then was dried and weighed. The final product was dimethyl tertraphenylpthalate (0.086 g, 0.172mmol, 61.42%).
The isomerization procedure was done in order to create dimethyl fumarate from dimethyl maleate. Dimethyl maleate and dimethyl fumarate are cis and trans isomers, respectively. This procedure was done via a free radical mechanism using bromine. The analysis of carvones reaction was done in order to identify the smell and optical rotation of the carvone samples that were provided. The odor was determined by smelling the compound and the optical rotation was determined using a polarimeter.
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.
To this mixture,3-4drops of concentrated sulfuric acid is added and the mixture is swirled. This will speed up the reaction.
A small piece of cotton is then put into the bottom of the column, along with a 0.5 cm thick layer of sand (put on top of the cotton). 20 mL of petroleum ether, and with a dry funnel on top of the column, 7 g of alumina (Aluminum Oxide) is put into the column. To ensure that no alumina adheres to the sides, a glass rod in a rubber stopper can be put to use through the gentle tapping of the column with it; in addition, additional petroleum ether can also be put to use by rinsing the inner walls of the column with it. To cover the alumina, another 0.5-1 cm layer of sand is put to use. For the solvent to drain into an Erlenmeyer flask, the stopcock is to be open until the solvent level exactly reaches the top of the alumina, where the stopcock is then immediately shut off in order to prevent air bubbles from developing in the solid support. To load the sample into the column bed, 0.5 mL of a pre-made solution, containing 200 mg of fluorine and 9-fluorenone, as well as 0.5 mL of petroleum ether is to be carefully put on top of the column bed with a Pasteur pipet. At this point, the stopcock is to be open again until the top of the liquid level is at the top of the alumina. Next, with 1 mL of petroleum ether, the addition and draining process is then done a total of three more times, where upon the third draining, 10 mL of petroleum ether is be put into to the top of the column bed and put to drain into a small beaker (label it “Fraction 1”). After every 2-3 mL, a watchglass is used to collect a drop of eluent to determine if all white solid has been eluted (there may be a need of 10-20 mL of petroleum ether). Once all eluted, another small beaker (label it “Fraction 2”) can replace the beaker for “Fraction 1.” In “Fraction 2,” 5 mL of petroleum ether is used to elute (stop when yellow band starts to elute), followed by a change of eluent to dichloromethane.
Plontke, R. (2003, March 13). Chemnitz UT. TU Chemnitz: - Technische Universität Chemnitz. Retrieved April 1, 2014, from http://www.tu-chemnitz.de/en/