Preparation and Sn1 Reactivity of 2-Bromobutane

Preparation and SN1 Reactivity of 2-Bromobutane Whitney Bellido Department of Chemistry, Illinois press out University, Normal, IL 61790-4160 Submitted April 4th, 2013 Introduction The overall goal of this experiment is to realise and be familiar of SN1 reactivity. We also learned how to prep atomic number 18 2-Bromobutane by learning how to rarefy and extract this product from its organic layer. Finally, an another(prenominal) goal was to specifically understand the relative reactivity of alkyl halides under SN1 conditions by reacting the alkyl halide and silver grey nitrate in ethanol.Results and Discussion The Overall Reaction The Proposed Mechanism data-based Procedure To prepare the 2-Bromobutane you must fill a 100 mL round bottom flask with 20 mL of 12M sulfuric erosive and 7. 4 mL of 2-butanol. Then add 8. 0 g of ammonium bromide along with a magnetic stir bar. Then stick to the flask to the apparatus, which is mounted on a Thermowell over a stirrer and a condenser atta ched to it, along with the thermometer in the flask. Then the mix was heated at 90oC then unplowed at the range of 90oC-100oC for 30 minutes.When that is completed add 20 mL of water into the flask to fare a simple distillation to collect the distillate in a graduated cylinder, keep doing this until there is no more 2-Bromobutane collected. Use a Pasteur pipette to draw off the organic layer to another container. come the potassium carbonate to allow the liquid to dry by swirling it. at a time this is completed the reactivity of alkyl halides under SN1 conditions was tested. Adding two drops of our product and the other different compounds into different test tubes along with 1mL of ethanolic silver nitrate reagent.We are comparing these by seeing how they react and if there is no response after 5 minutes we will place the test tubes in a beaker of water that is heated at a temperature of 70oC-80oC and observe what happens. data-based Stoichiometry Compound Molecular Weight Qua ntity Moles 2-Butanol 74. 122 g/mol 7. 41 mL (6. 01 g) 0. 081 Sulfuric Acid 98. 079 g/mol 20. 1 mL 0. 242 Ammonium Bromide 97. 94 g/mol 8. 02 g 0. 082 The change reagent is the 2-Butanol. Yield Data Product Name 2-Bromobutane Molecular Weight 137. 02 g/mol Boiling Point Range 89C-91C metaphysical Yield (Moles) 0. 081 moles Theoretical Yield (grams) 11. 09 grams factual Yield (grams) 6. 84 grams Actual Yield (moles) 0. 05 moles Percent Yield 62% NMR table mansion Chemical Shift (ppm) Multiplicity Integration A 4. 1 ppm sextette 1 B 1. 85 ppm Pentet 2 C 1. 7 ppm Doublet 3 D 1. 05 ppm Triplet 3 Reactivity of Alkyl Halides Compound means Temperature hotness 1-Bromobutane After 30 assists, the mixing was a cloudy whitish color but no precipitate organize After 5 minutes, it changed into a yellow color with precipitate formed. 2-Bromobutane After 30 seconds, the mixture was a light yellowish color and a precipitate formed instantly. Not heat 2-Bromo-2-methylpropane After 30 seconds, the mixture was yellow and a precipitate formed instantly. Not Heated Compound Room Temperature Heating 1-Chlorobutane After 30 seconds, the mixture was clear. After 5 minutes, the color changed slightly to duster and lightly cloudy. 2-Bromobutane After 30 seconds, the mixture was a white cloudy color and formed a precipitate instantly. Not Heated 2-Iodobutane After 30 seconds, the mixture was yellow and precipitated instantly. Not Heated end In conclusion, the SN1 reply of 2-Bromobutane was performed. According to the Yield Data table, when the actual apply and theoretical yield are calculated we can get the share yield, which was 62%. At least this number was higher than 50% I can understand how this could have happened. When I was drying the reagent with potassium carbonate, prior to that I had put the other pellets, which were calcium chloride on accident.This probably affected my per centum yield also with the fact that the temperature was not well ma intained it kept fluctuating under 90OC. According to the reactivity of alkyl halides, the results of these tables can conclude the theories of the conditions of SN1 reactions. The first table states that the tertiary carbocation are more stable which allows this reaction to perform faster than second and primary structured carbocations. Then the second table can concludes that iodine is the best leaving group because it is a much weaker base than the bromide ion and chloride ion causing it to react faster.