Organic Lab 7

Amanda Jornd Experiment 7- Synthesis and Reactivity of tert-Butyl Chloride Via an SN1 Reaction Introduction/Background alkyl group halides are compounds in which a halogen atom replaces a hydrogen atom of an alkane. Alkyl halides are classified advertisement as primary, secondary or third depending on the number of alkyl substituents directly attached to the vitamin C attached to the halogen atom. The purpose of this lab was to properly prepare t-butyl chloride from t-butyl- alcohol in a concentrated hydrochloric acid.The reaction occurs through a nucleophilic substitution, which is when a nucleophile replaces the leaving group in the substrate. In this lab, the hydroxyl group of t-butyl alcohol is replaced by a chlorine atom. The reaction proceeds through an SN1 mechanism (Weldegirma 38-41). A nucleophile is any neutral or uncharged molecule with an unshared pair of electrons. In the substitution reaction, the nucleophile donates an electron pair to the substrate, leading to th e institution of a new bond to the nucleophile, while breaking the existing bond to the leaving group (Solomons and Fryhle 99-102).The ii qualitys of nucleophilic substitution reactions, SN1 and SN2, are identified based on whether the different steps occur simultaneously (SN1) or in two separate steps (SN2). To synthesize the t-butyl chloride, the t-butyl alcohol goes through an SN1 reaction. Also, the nature of the solvent poop affect which substitution reaction will occur. Polar protic solvents typically favor SN1 reactions. This is because the SN1 mechanism is carried surface in two steps and the polar protic solvent produces both a cation and an anion which are capable of stabilizing the charges on the ions organize during the reaction.Because an SN2 reaction occurs in one step, this is unfavorable however, the SN2 reactions tend to favor polar aprotic solvents. A nonher performer affecting the type of substitution reaction is the nature of the leaving group. Since the S N1 reactions occur in one step, they broadly require an excellent leaving group and wont typically run with a unfortunate leaving group. The SN2 reaction also favors excellent leaving groups but can run with any type of leaving group because it is run in two different steps. To synthesize the t-butyl chloride, the t-butyl alcohol goes through an SN1 reaction. Weldegirma 38-41). appliance of the preparation of tert-butyl chloride Possible side reaction during the preparation of tert-butyl chloride Experimental Section/Flow Chart composition 1 60mL separatory funnel shape + cooled 15mL of concentrated HCl to 0? C + added 15mL of HCl to separatory funnel + added 5mL tert-butyl alcohol +swirled it without the secure for 20 proceedings + permit stand until two distinct layers were form + drained lower layer into Erlenmeyer flask and relieve just incase Organic spirit level- in separatory funnel +added 30mL of DI water + swirled for a few legal proceeding let stand until two dis tinct layers formed + move off lower layer into Erlenmeyer flask and saved just incase Organic Layer- in separatory Funnel + added 15mL of 5% sodium bicarbonate + shook with s swipeper with venting + let stand for a few proceeding until two distinct layers formed + drew off lower layer into Erlenmeyer flask and kept just incase Organic Layer- in separatory funnel + added 15mL of water + swirled for a couple minutes + let stand until two distinct layers have formed + drew off lower layer into Erlenmeyer flask and kept just incase Organic Layer transferred product layer into clean/dry 125 mL Erlenmeyer flask + added 1. 5 grams of anhydrous atomic number 20 chloride to dry the product +decanted into round bottom flask + added 6 boiling stones + ran through a fair distillation Tert-Butyl Chloride Part 2- strain render 1- + added . 1mL tert-butyl chloride from incite 1 + added 1mL of NaI + shook while property top of test tube with finger + recorded time, look, color, and so forth Negative Result Test Tube 2- + added . 1mL tert-butyl chloride from part 1 + added 1mL of AgNO3 + shook while holding top of test tube with finger recorded time, look, color, etc. Positive Result Test Tube 3- + added . 2mL tert-chloro butane + added 1mL of NaI + shook while holding top of test tube with finger + recorded time, look, color, etc. Positive Result Test Tube 4- + added . 2mL tert-chloro butane + added 1mL of AgNO3 + shook while holding top of test tube with finger + recorded time, look, color, etc. Negative Result dishearten of Chemicals carry over of Chemicals 1 Table of Chemicals 1 Chemical Name- Physical Properties- Chemical Properties- Tert-Butyl Alcohol- M. P. -25-26 ? CB. P. 82-83? CMolecular Weight- 74. 2 g/molWater Solubility- miscible Combustible- noFlammable- yes Hydrochloric Acid- M. P. -114? CB. P. -85. 05? CMolecular Weight-36. 4 g/mol Combustible- yesFlammable- no atomic number 11 bicarbonate-(Chembook) (Chembook) M. P. 50? CB. P. 851? CMolecul ar Weight- 84 g/molWater Solubility- 9 g/ 100mL Combustible- noFlammable-no Table of Chemicals 2 Table of Chemicals 2 Tert-butyl chloride- M. P. -26? CB. P. 51? CMolecular Weight- 92. 57 g/molWater Solubility- sparingly Combustible- noFlammable-yes Anhydrous calcium chloride- M. P. 772? CB. P. 1935?CMolecular Weight- 110. 98 g/molWater Solubility- 74. 5 g/ 100mL Combustible- yes/ slightlyFlammable- no Silver nitrate- M. P. 212? CB. P. 444? CMolecular Weight- 169. 87 g/molWater Solubility- 122 g/100mL Combustible- noFlammable- no Sodium iodide-(Chembook) (Chembook) M. P. 661? CB. P. 1304? CMolecular Weight- 149. 89 g/molWater Solubility- 178. 8 g / 100mL Combustible- noFlammable- no Table of Chemicals 3 Table of Chemicals 3 1-chlorobutane- (Chembook) (Chembook) M. P. -123? CB. P. 78? CMolecular Weight- 92. 57 g/molWater Solubility- . g/L Combustible- YesFlammable-Yes Results Percent Yield- t-butyl alcohol Density = Mass/Volume M= . 842 x 5 = 4. 21 grams Mass/ M. W. = m oles 4. 21 g / 74. 12 g/mol = . 0568 moles of t-butyl alcohol t-butyl chloride Density = Mass / Volume M= . 397 x 2 = . 794 grams mass / M. W. = moles . 794 g / 92. 57 g/mol = . 00858 moles of t-butyl chloride Because of a 11 ratio wherefore you can use actual / theoretical x 100 . 00858 moles / . 0568 moles x 100 = 15. 105 % Results Table 1 Results Table 1 contort Precipitate appearance Time of settle After warm water (50?C) bath Positive or Negative Result Test Tube 1- T-butyl chloride & NaI Clear/ faint tint of yellow No precipitate Over 6 minutes and still no precipitate Nothing occurred later 6 minutes in the steam bath Negative Result Test Tube 2- T-butyl chloride & AgNO3 Cloudy and white Yes, puny solid particles . 8 seconds N/A Positive Result Test Tube 3- t-chloro butane & NaI Slightly marshy with initial drop but quickly turned clear No precipitate after 6 minutes 6 minutes RT, for steam bath 4 minutes 58 seconds Yellow dissolvent as well as white precipita te on bottom formed. Positive Result Test Tube 4- t-chloro butane & AgNO3 Clear colorless liquid No precipitate 6 minutes RT, 6 minutes steam bath No precipitate Negative Result Discussion Throughout this lab, the main finish was to properly create a t-butyl chloride. In order to test if we properly received our product we tested the sample with two different solvents, a solvent of sodium iodide and ash gray nitrate. If an alkyl halide is a tertiary one, it can easily react with a solvent of fluent nitrate to generate a comparatively stable tertiary carbocation through an SN1 reaction.If an alkyl halide is a primary one, it can then react with iodide ions in the sodium iodide solvent by an SN2 mechanism showing a precipitate of insoluble sodium chloride. raise up can also be used in this cover to speed up the reaction (Weldegirma 38-41). The depression test we ran was t-butyl chloride and sodium iodine. After mixing the two compounds, there was only a slight tint to the liquid but remained clear and precipitate free for 6 minutes of being room temperature. We then placed it in a warm water in which there was no precipitate that formed while being heated.This test yielded a forbid result. The second test that we ran was t-butyl chloride and silver nitrate. Directly after mixing the compounds, there was an immediate white precipitate that had formed. This test yielded a positive result. A negative result with sodium iodide and a positive result of silver nitrate concluded that our solution of t-butyl chloride was a pure tertiary alkyl halide. Our third test was run with t-chloro butane and sodium iodide. This test initially did not form a precipitate while it was kept at room temperature.We then used a warm water bath in which after 5 minutes the solution formed a white precipitate and a yellow liquid. This shows that this test was a positive test. The fourth test was with t-chloro butane and silver nitrate. This test did not form a precipitate at room te mperature or during the steam bath. This shows a negative result. With the t-chloro butane, the negative result with silver nitrate and the positive result of sodium iodide prove that this is and then a primary alkyl halide. ConclusionIn this lab, we properly carried out an SN1 reaction from t-butyl alcohol to t-butyl chloride and tack together that we did in fact create a t-butyl chloride by getting a positive result from our silver nitrate test in the end. Although we werent able to visibly see with our eye the nucleophilic attack, the steps that we carried out in the lab showed the separated layers and that there were reactions going on during each step. The organic layer that was interminably washed was undergoing the slow reaction process during each separating stage.In the end, after the distillation of the solution, the SN1 reaction was completely carried out. The teaching from this data has revealed that it is possible to carry out an SN1 reaction in a lab however, in the process of washing the product there will be a lot of material lost braggy a low percent yield in the end. It would be smart to use chemicals that are bum and in large quantities to carry out these types of reactions. The information and techniques performed in this lab could be applied to otherwise situations in an industrial setting.One example of this could be creating chlorofluorocarbons which used to be produced for aerosol cans and other products. Although these are no longer widely used in the world due to ozone effect, the SN1 reaction could be done with these chemicals. Overall, the lab accomplished what it was set out to do. References Chemical Book. 2008.