Preparation of Phenyl Benzoate

TITLE: PREPARATION OF PHENYL BENZOATE

Table of Contents
1. Introduction................................................................................................................................1
1.1 Background...........................................................................................................................1
1.2 Objectives.............................................................................................................................3
1.3 Hypothesis............................................................................................................................3
1.4 Problem statement................................................................................................................3
2. Literature review.........................................................................................................................3
2.1 Esterification.........................................................................................................................5
2.2 Equilibrium reactions............................................................................................................7
3. Methodology.............................................................................................................................10
3.1 Procedure......................................................................................................................10
4. References................................................................................................................................14

1. Introduction
1.1 Background
Phenyl benzoate is classified as an ester which is a wide class of organic compounds. It is
a white powder. Phenyl benzoate is the product of three reactants including NaOH
(sodium hydroxide), benzoyl chloride and phenol. At room conditions, the compound is a
solid. However, it can turn into an oily liquid with a slight increase in temperature.
Several types of polyesters used in the clothing industry as well as other organic
industries utilize Phenyl benzoate.
Esters are derived from carboxylic acids and they have the general molecular formula
RCOOR′ in which R varies from alkyl groups to hydrogen atoms. The reaction of a
carboxylic acid with excess alcohol with a catalyst to speed up the reaction produces an
ester. This reaction is named after Emil Fischer a chemist from Germany and it is termed
as the Fischer esterification (Van Santen, Markvoort, Filot, Ghouri, & Hensen, 2013). The
reaction involves acid reflux with excess alcohol such as ethanol and with about 0.03
HCl. The reaction is represented by the equation below
H*RCOOH + R'OH RCOORM- H2O
Esterification is an extensively used process in the production of organic compounds in
industries. Esters can be assigned many different classes stretching from aromatic esters
(those with a sweet smell and several functional groups as well as substitution groups).
Organic esters are important intermediate products in many chemical processes. They are
found in many products we use today such as plastics, solvents, perfumes. Esters are
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mostly used as plasticizers, solvents, perfumery as well as constituent reactants in various
industrial reactions to produce pharmaceuticals, agrochemicals. Usually the reaction that
produces esters (esterification) reaches equilibrium soon after starting. This means that
both the products and reactants reach the same level of concentration hence the reaction
cannot proceed in any direction. In practice, this slows down the reaction and lowers the
yield of the desired product. The ordinary process of esterification is one of equilibrium.
A mixture of an acid and an alcohol in stoichiometric proportions usually attains
equilibrium at about 68% (Martin, 2011) of conversion for an alcohol with all the valence
bonds filled (that is, a saturated alcohol). For high product yield Le Chatlier’s principle
must be applied. The process involves shifting the equilibrium towards the products side
or the forward direction in other words. This is achieved via one of the following ways:
Eliminating one of the products, (water or the ester) immediately it is formed to maintain
a high concentration gradient. Usually, water is the product to get rid of and it is removed
using organic solvents or by using dehydrating agents like calcium oxide, CaO. The other
method employed to boost the yield involves use excess reactant, either the alcohol or
acid.
Phenyl benzoate has a molecular formula of the form C13H10O2. The molecular mass is
about 198.2212g. The boiling point is between 298º C and 299º C and the melting point is
between 68ºC and 70ºC (Armarego & Chai, 2009). At normal room temperatures, the
substance appears as a white crystalline powder. It is also known by other names such as
phenyl ester, benzoic acid or Diphenylcarboxylate. Esters are a wide class of organic
compounds that form acids or alcohols when reacted with water. To form the ester, an
acid reacts with an alcohol and water is eliminated in the process. Most types of esters are
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