Preparation and Purification of an Alkyl Halide

Preparation and Purification of an Alkyl Halide

Bryan B. Arguilles

Department of Food Science and Nutrition, University of the Philippines, Diliman, Quezon City

Date Performed: February 26, 2015

Date Submitted: March 10, 2015

Abstract

The study demonstrated the processes involved in the synthesis of an alkyl halide, particularly tert-butyl chloride, from tert-butyl alcohol, a tertiary alcohol with the aid of cold concentrated HCl, a hydrohalide. The process is known to be governed by unimolecular nucleophilic substitution (SN1) reaction mechanism. 20 mL of cold concentrated HCl was added to 10 mL of tert-butyl alcohol in a separatory funnel to yield the aforementioned alkyl halide. Simple distillation was performed afterwards to purify the product collected. The experiment was able to provide 6.048 g final product or 62.47% of the calculated theoretical 9.68 g tert-butyl chloride gain. Results from this study showed that the synthesis of tert-butyl chloride may be deemed successful. On the other hand, the 37.53% loss may have been caused by some side reactions, errors committed by the experimenters such as inaccuracy in the proportion of reagents, and inevitable environmental factors. Nevertheless, it has provided an accurate background regarding the basic concepts of the SN1 reaction mechanism and the synthesis of an alkyl halide itself.

I. Introduction

Organohalides refer to those compounds containing one or more halogen atoms. Good examples of these are the alkyl halides. As the name suggests, halogen atoms in an alkyl halide are bonded to an alkyl group with saturated, sp3-hybridized carbon atom. These halogen atoms are considered substituent to the hydrocarbon parent chain. Because of the difference in the electronegativity of carbon and halogen atoms, alkyl halides are classified as polar compounds. The carbon atoms bear a slightly positive charge while the halogens carry a slightly negative charge. This implies that alkyl halides act as electrophiles...