Conversions of Alcohols to Alkyl Halides: 1-Propanol and 2-Pentanol Introduction One way scientist gets alkyl halides is by using the manipulation of an alcohol. When alcohols are treated with HBr or HCl; they can undergo a nucleophile substation reaction to generate an alkyl halide and water2. Using the structure of the alcohols they are able to use SN1 or SN2 mechanisms. For both these mechanisms though, the –OH group must be pronated shown in Figure 1. R—OH + H—Br + R—OH2 +Br- Figure
Conversion of Alcohols to Alkyl Halides Ankita Patel August 6, 2013 Introduction This lab consisted of the conversion of alcohols into alkyl halides through common substitution methods. These methods include SN1 and SN2 mechanism, both of which can occur for this type of reaction. For both reactions, the first step of protonation will be to add hydrogen to the –OH group and then the rest of the reaction will proceed according to the type of mechanism. SN1 reactions form a cation intermediate
Conversion of Alcohols to Alkyl Halides Title: Conversion of Alcohols to Alkyl Halides Abstract: In this experiment the conversion of alcohols to alkyl halides are investigated through reflux and simple distillation. These are common procedures used to separate substances. After the reflux and distillation is complete 13C NMR and IR spectrum is used to identify the product or products for each reaction: 1a, 1b, and 2. Every individual in the group was assigned either 1a (1-propanol) or 1b (2-pentanol)
an alcohol is in the hydroxyl functional group (-OH) is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms. Important alcohols are the simple acyclic alcohols. Of those, ethanol (C2H5OH) is the type of alcohol found in alcoholic beverages, and in common speech the word alcohol refers specifically to ethanol. When it comes to alcohol reactions the functional group of the alcohols is the hydroxyl group –OH. Unlike the alkyl halides
Discussion and Conclusion: Preparation of 1-Bromobutane The purpose of this experiment was to demonstrate the conversion of a primary alcohol, 1-butanol, to a primary bromoalkane, 1-bromobutane, a SN2 reaction. The conversion of 1-butanol to 1-bromobutane relies on sulfuric acid which plays two important roles. First, it protonates the alcohol of 1-butanol to form an oxonium ion which is a good leaving group. Secondly, it produces the hydrobromic acid, the nucleophile, which attacks 1-butanol
from 1-butanol by SN2 reaction Objective: 1. To study the preparation of 1-bromobutane from 1-butanol by an SN2 reaction 2. To study the method of purification of an organic compound by simple extraction 3. To study the test of identification of alkyl halide Chemicals and Apparatus: ~18.0 g 1-butanol, ~20.0 g sodium bromide, 15 ml of concentrated sulfuric acid, anhydrous magnesium sulfate, ~10 ml of 5% aqueous sodium bicarbonate, ~1 ml of sodium iodide – acetone reagent, 1 ml of bromine in chloroform
hydroxide, to yield a carboxylic acid but most of the time either an alkoxide base or an amine to yield an ester or an amide.2. and 5. This rearrangement proceeds through a carbanion which attacks an endocyclic carbon and expels a leaving group (a halide) forming a bicyclic molecule with rings smaller than the original substrate.4 The bicycle is then opened by nucleophilic attack on the ketone to give the contracted product.4 Scheme 2: A Typical Favorskii Rearrangement20 Scheme 3: A typical Favorskii