SN1 Reaction: Preparation of Cyclohexyl Chloride

DISCUSSION

        Experiment 8 examined SN1 reactions which are reactions that synthesize alcohols where the rate-determining step in uni-molecular. This reaction contains a leaving group which leaves resulting in a carbocation that is immediately attached by a nucleophile that is commonly a weak base. 3 The rate of reaction increases if the solvent becomes more polar because a more polar solvent would ensure a more stable carbocation as the leaving group breaks away. A reflux setup was used because heat was needed for the reaction, but none of the reactants should be discarded.

        Zinc chloride was use because it accepts the lone pair from the –OH group and it helps cleave the C-O bong. Before the heating, it is important to swirl the mixture until a permanent yellow color is present because it will ensure that the reactant are mixed and this will aid in the reaction process. It is also important to perform most of the procedure under the hood due to the noxious fumes of the reagents being used. The mixture was heated for quite some time in order to ensure the collisions of the reactants, thereby increasing the rate of the reaction along the desired product.

 Liquid-liquid extraction was performed through the use of a separatory funnel after heating. Only the organic layer was desired, so it was necessary to separate it from the remaining HCL and ZnCl2. Water used to rinse the R.B flask was used to wash the organic layer to ensure that there was none of the mixture was left over. 4 If there is still a large amount of water in the organic layer, the funnel should be vigorously shaken before drying and then separated, additional sodium bisulfate can be used. Sodium bisulfate is used to aid with the purification process as a mild reducing agent to help increase the yield of cyclohexyl chloride. Drying agent is used to absorb any impurities from the aqueous layer.

        The experiment as successful, cyclohexyl chloride was produced and identified through the silver nitrate qualitative test. There were also some traces of the alcohol left which can be seen from the chromic acid test. However, the percent yield was low due to the drying process which may have absorbed most of the product.

Percent Yeild: 2.2 mL / 5.0 mL= .44 mL x 100% = 44%  

REFERENCES

McMurr, John. Organic Chemistry: Philippine Edition. Pasig: Cengage Learning Asia, 2010. Print

“Sn1 and Sn2” Organic Chemisty, Wavesignal.com http://www.wavesignal.com/o_chem/Nucleo_1.htm