Nucleophilic Substitution: Synthesis of N-Butyl Bromide and T-Pentyl Chloride
Nucleophilic Substitution | Synthesis of n-Butyl Bromide and t-Pentyl Chloride | | Jessica | [Pick the date] |
Abstract
The synthesis of the alkyl halide n-Butyl Bromide from alcohol is the foundation for the experiment. During the isolation of the n-butyl bromide, the crude product is washed with sulfuric acid, water, and sodium bicarbonate to remove any remaining acid or n-butyl alcohol. The primary alkyl halide halide n-butyl bromide is prepared by allowing n-butyl alcohol to react with sodium bromide and sulfuric acid. The sodium bromide reacts with sulfuric acid to produce hydrobromic acid . Excess sulfuric acid acts to shift the equilibrium and speed up the reaction by producing a higher concentration of hydrobromic acid. The sulfuric acid protonates the hydroxyl group of n-butyl alcohol so that water is displaced instead of the hydroxide ion OH-. The acid also protonates the water as it is produced in the reaction and deactivates it as a nucleophile. Deactivation of water keeps the alkyl halide from being transformed back to the alcohol by nucleophilic attack of water. The reaction of the primary substrate continues via an SN2 mechanism.
Introduction
Halogenoalkanes, also known as haloalkanes or alkyl halides, are organic compounds in which one or more hydrogen atoms in an alkane have been replaced by halogen atoms, fluorine, chlorine, bromine or iodine. In carbon-halogen bond, halogens have significantly greater electronegativities than carbon except iodine. In result, this group is polarized so that the carbon is electrophilic and the halogen is nucleophilic. Halogenoalkanes can be classified depending on the halogen atom position on the chain of carbon atoms. The carbon which is attached with the halogen atom is linked up with only one other alkyl group in primary halogenoalkanes, whereas directly linked up with two and three other alkyl groups in secondary halogenoalkanes and tertiary halogenoalkanes. In some instances, primary halogenoalkanes
Abstract
The synthesis of the alkyl halide n-Butyl Bromide from alcohol is the foundation for the experiment. During the isolation of the n-butyl bromide, the crude product is washed with sulfuric acid, water, and sodium bicarbonate to remove any remaining acid or n-butyl alcohol. The primary alkyl halide halide n-butyl bromide is prepared by allowing n-butyl alcohol to react with sodium bromide and sulfuric acid. The sodium bromide reacts with sulfuric acid to produce hydrobromic acid . Excess sulfuric acid acts to shift the equilibrium and speed up the reaction by producing a higher concentration of hydrobromic acid. The sulfuric acid protonates the hydroxyl group of n-butyl alcohol so that water is displaced instead of the hydroxide ion OH-. The acid also protonates the water as it is produced in the reaction and deactivates it as a nucleophile. Deactivation of water keeps the alkyl halide from being transformed back to the alcohol by nucleophilic attack of water. The reaction of the primary substrate continues via an SN2 mechanism.
Introduction
Halogenoalkanes, also known as haloalkanes or alkyl halides, are organic compounds in which one or more hydrogen atoms in an alkane have been replaced by halogen atoms, fluorine, chlorine, bromine or iodine. In carbon-halogen bond, halogens have significantly greater electronegativities than carbon except iodine. In result, this group is polarized so that the carbon is electrophilic and the halogen is nucleophilic. Halogenoalkanes can be classified depending on the halogen atom position on the chain of carbon atoms. The carbon which is attached with the halogen atom is linked up with only one other alkyl group in primary halogenoalkanes, whereas directly linked up with two and three other alkyl groups in secondary halogenoalkanes and tertiary halogenoalkanes. In some instances, primary halogenoalkanes
References: Clark, J. (2004). Nucleophilic Substitution. Retrieved November 13, 2012, from http://www.chemguide.co.uk/mechanisms/nucsub/whatis.html#top Pavia DL, Lampman GM, Kriz GS, Engel RG. (2011). A Small Scale Approach to Organic Laboratory Techniques. Location: Unknown. Publisher: Mary Finch (August 10, 2006). Retrieved November 13, 2012, from http://www.chem.ucla.edu/~bacher/General/30BL/gc/theory.html Chromatography. Introductory Theory. Retrieved November 13, 2012, from http://teaching.shu.ac.uk/hwb/chemistry/tutorials/chrom/chrom1.htm