Synthesis and Reactivity of tert-butyl chloride PDF

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Synthesis and Reactivity of tert-Butyl Chloride via an SN1 ReactionEvan KirkMinghui WangCHM2210L:IntroductionIn this experiment a substitution reaction occurs creating a new product from the reaction. A substitution reaction occurs when the functional group of one compound is then replaced by a subs...

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Synthesis and Reactivity of tert-Butyl Chloride via an SN1 Reaction Evan Kirk Minghui Wang CHM2210L:914 Introduction In this experiment a substitution reaction occurs creating a new product from the reaction. A substitution reaction occurs when the functional group of one compound is then replaced by a substituted functional group. This occurrence is also known as a displacement reaction and is in common occurrence between acid-base reactions. A common model for the dissociative reaction is the SN1 mechanism, also known as first-order nucleophilic substitution. In this, the step which determines the rate of the reaction only contains one molecule (Master, 2020). There are SN1 and SN2 reactions in which they are affected by relatively the same factors. A common factor being the solvent and the leaving group of the reaction. For example, polar aprotic solvents are not used in such reactions due to being able to react with present carbocation intermediate producing an unwanted product that can sway the results of the experiment (Libre, 2020). In SN1 reactions the rate in which the departure of the leaving group occurs can be influenced and affected by the addition of tertiary alkyl halide. This can cause for the rate to increase and produce a carbocation that is more stable or a polar solvent (Libre, 2020). As for SN2 reactions, the affecting factors are things such as nucleophile strength, structure of present alkyl group, the ability of the leaving group, C-X bond strength, and the stability of the group after leaving (Walker, 2021).

In the preparation of tert-butyl chloride a mechanism called arrow pushing outlines the movement of elections throughout the course of a reaction to track the pacing and overall progression of the reaction. This kind of mechanism can be seen in the transfer of electron from the lone pair attached to the OH group of the tert-butyl alcohol to the present Hydrogen within the Hydrochloric Acid. This illustrates the movement of electrons occupied in lone pair and bonds lines and allows for the representation of the bonds broken and the forming of new product compounds. From the reaction in the preparation of tert-butyl chloride undesired side products are can occur due to unstable conditions that the reaction might take place under. For example, if the reaction exceeds a comfortable temperature the formation of isobutylene. This reaction can be seen below(Weldegirma, 2019).

Experimental Section Synthesis of tert-butyl chloride Obtain 15mL of HCl and add to separatory funnel. Swirl uncapped for 15-20 minutes, after, discard aqueous

Wash with 30mL of D.I. water, discarding aqueous layer, then washing with 13-15mL of 5% sodium

After wash is complete, stop the funnel, vent and discard aqueous layer

Remove the product and wash was 1015mL of D.I. water and transfer to beaker

Record the weight of the product and the boiling point

Collect the receiving vial and weigh

With the solution added, assemble distillation apparatus and begin process

Get 1g of anhydrous calcium chloride and decant and add to a flask

Qualitative test for reactivity Get (4) test tubes and label accordingly

In test tube 1, add 0.1mL of tert-butyl chloride, 1mL of 18% NaI in acetone, then cover and shake, record results

In test tube 2, add 0.1mL tert-butyl chloride, 1mL AgNO3, then cover and shake, record results

In test tube 3, add 0.2mL of 1-chlorobutane, 1mL of NaI, then cover and shake, record results

In test tube 4, add 0.2mL of 1-chlorobutane, 1mL of AgNO3, then cover and shake, record results

Chemicals (Pubchem, 2021) Chemical Formula Structure

Mass Melting Point Chemical Property

Physical Property

Sodium Bicarbonate NaHCO3

Tert-Butyl Alcohol C4H10O

Silver Nitrate

Hydrochloric Acid HCl

Tert-Butyl Chloride C4H9Cl

Acetone

84.01 g/mol 50.0 ℃ Monosodium salt, alkalinizing and electrolyte replacement properties, White crystal powder, odorless, slightly alkaline

74.12 g/mol 25-26 ℃ Tertiary alcohol, derived from hydride of an isobutane

169.87 g/mol 212 ℃ Antiseptic properties, sclerosing agent, trigonal planer

34.46 g/mol -114.2 ℃ Dissolves in water, very acidic pH

92.57 g/mol -26 ℃ Organochloride, soluble in water, undergoes hydrolysis

58.08 g/mol -95 ℃ Organic solvent, occurs naturally, breakdown product of animal fat

Colorless oily liquid, floats on water, irritating vapor

Colorless or white solid, black with light exposure, used in photographic films

Corrosive Colorless liquid, liquid, dense flammable white vapor, heavier than air

Colorless, flammable, volatile, found naturally, less dense than water

AgNO3

C3H6O

Chemical Formula Structure

Anhydrous Calcium Chloride CaCl2

1-Chlorobutane C4H9Cl

Sodium Iodine NaI

Mass Melting Point Chemical Property

110.98 g/mol 772 ℃ Salt, inorganic chloride, used in fertilizer Off-white solid, sinks in water

92.57 g/mol -123.1 ℃ Flammable, used in production of organic chemicals White liquid, slightly soluble, vapors heavier than air

149.59 g/mol 661 ℃ Metal iodide salt, inorganic salt

Physical Property

Water-soluble, used to evaluate thyroid function

Results

Chemical Tert-butyl chloride

Mass (g) 3.72

% Yield 76.86

Test Tube

Color of

Appearance of

Time of Precipitation

Qualitative Test Results

1 (tert-butyl chloride

Precipitate Faint yellow

Precipitate No Precipitate

Slow

Negative

and NaI) 2 (tert-butyl chloride

Cloudy opaque

White cloudy

Rapid

Positive

and AgNO3) 3 (1-Chlorobutane

purple Yellow

precipitate Chunky small

Rapid

Positive

Faint clear color

precipitate No Precipitate

Slow

Negative

and NaI) 4 (1-Chlorobutane and AgNO3)

Calculations

Moles (tert −butanol)=

3. 875 g/mol Mass of t−butanol =0.0523 mol = molar mass of t −butanol 74.12 g/mol

Moles (t −butyl chloride) =

Mass of t−butyl chloride 3.72 g /mol =0.0 402mol = molar mass of t−butyl chloride 92.57 g /mol

Percent Yield of t−butyl chloride=

0.0402 mol Actual Yeild =7 6.86 % = TheroreticalYeild 0.052 3 mol

Discussion This experiments purpose was to extract and synthesize tert-butyl chloride using the proper SN1 reaction. In the experiment the percent yield came out to be 76.86%, this is significantly higher than the 50% mark. The possibility of getting a percent yield of 50% or less comes down to unseen error incorporated in the experiment. This can be in the form of inaccurate measurements being made with the tert-butyl alcohol. If the adequate amount of tertbutyl alcohol was not used, it can cause for a lower amount of synthesized tert-butyl chloride with the addition of HCl. Another possible deviation can come from if the temperature wasn’t regulated properly, this could cause for the formation of the unwanted side product. This can use some of the present alcohol that will no longer be able to react and synthesize the full possible amount of tert-butyl chloride. In this experiment simple SN1 reactions took place in which substitution occurred during the synthesis of tert-butyl chloride. The first of the reactions being between tert-butyl alcohol and HCl, this resulted in formation of the present tert-butyl chloride. From this we were able to isolate the tert-butyl chloride through methods of distillation. Subsequent reactions were them induced through the addition of NaI in acetone, 1mL of AgNO3, and 1-Chlorobutane in different combinations. These reactions were performed in order to test the qualitative reactivity between tert-butyl chloride and the subsequent chemicals. Form the reactions that took place in the test tubes, there weren’t many deviations from the prior theorized reactions that took place. This is due to the previous knowledge concerning the factors affected the speed and outcome of SN1 and SN2 reactions. As for test tubes 2 and 3, the reaction took place at a faster pace than I once thought it would. In test tubes 2 and 3, the presence of alkyl halide proved to benefit the reaction

taking place. This was due to the formation of the tertiary carbocation. This allowed for the reaction to take place as fast as possible as it was very stable.

Conclusion After the conclusion of the experiment, it appeared that the theoretical background and the results gather are indeed connected. This is can be seen in the percent yield of tert-butyl chloride, as we were able to retrieve 76.86%. This does not deviate far from the theorized value; a theorized amount of tert-butyl chloride was to be lost in the experiment due to the side reaction that would take place. This caused for a loss in potential product that could have been synthesized. From this, the experimental data revealed that we were able to moderately successful in the synthesis of tert-butyl chloride. Given the 76.86% yield, it proved the presence of the side reaction that was theorized to take place if the most stable reaction state wasn’t achieve. On top of this the data also confirmed the qualitative reactivity test as it confirmed interactions between the tested compounds. The methods used in this experiment are used most commonly in the testing of pharmaceuticals. Synthetization allows chemist to test interactions between compounds in a controlled setting to ensure adverse effects are avoided. This is a process utilized greatly by the FDA in the assurance of quality control in industries and manufacturing facilities (Chemical, 2021). Overall, the experimental accomplished what is set out to do as we were able to successfully synthesize tert-butyl chloride from tert-butyl alcohol and HCl. This then allowed for the success qualitative reactivity test to be carried out as necessary.

References

The SN1 reaction mechanism. (2020, December 18). Retrieved February 23, 2021, from https://www.masterorganicchemistry.com/2012/07/13/the-sn1-mechanism/ Libretexts. (2020, August 11). 6.7 factors Affecting (S_N1) REACTIONS. Retrieved February 23, 2021, from https://chem.libretexts.org/Courses/Purdue/Purdue_Chem_26100%3A_Organic_Chemistry _I_(Wenthold)/Chapter_06%3A_Alkyl_Halides.__Nucleophilic_Substitution_and_Elimina tion/6.07_Factors_Affecting_SN1_Reactions Walker, M. (n.d.). Organic chemistry 1: An open textbook. Retrieved February 23, 2021, from https://courses.lumenlearning.com/suny-potsdam-organicchemistry/chapter/8-3-factorsaffecting-rate-of-nucleophilic-substitution-reactions/ Chemical synthesis. (n.d.). Retrieved February 23, 2021, from https://www.britannica.com/science/chemical-synthesis Weldegirma, S. Experimental Organic Chemistry, 8th ed.; University of South Florida: Tampa, 2019....