Together we'll explore those organic chemistry labs we love oh so very much. In the event you find this near sunrise filled with anxiety, rage and confusion I hope this gives you a hand.
Hydrolysis of Methyl Salicylate and Synthesis of Acetylsalicylic Acid Objectives Many naturally occurring chemicals can be used isolated and used to make other compounds.
Methyl salicylate is a naturally occurring compound that we will use to produce salicylic acid, which will then be used to make the wonder drug aspirin acetylsalicylic acid.
This is not the source of salicylic acid in the industrial synthesis of aspirin, but it is, nevertheless, a good one for laboratory use. Two different chemical techniques will be employed.
First is hydrolysis, which is the breaking of a bond with water. Esters are quite easily hydrolyzed into their two starting components, an acid and an alcohol. Then, we perform an ester synthesis for the formation of aspirin.
Equilibrium favors hydrolysis, but using acetic anhydride as the acid source prevents this backward reaction, since water is not produced during ester formation.
Both salicylic acid and aspirin are easily isolated. Background Methyl salicylate an ester can be hydrolyzed to produce salicylic acid. The two different functional groups on the aromatic ring are utilized in this lab.
First, the free carboxylic acid group will be produced when we hydrolyze the methyl salicylate. Methanol is the alcohol which is released by hydrolysis.
Second, the hydroxyl group on salicylic acid will be used in ester formation to produce aspirin. When we performed an ester synthesis previously, we took special precautions to prevent water from being produced we included a dessicant in the reaction mixture and had a drying tube affixed on top of the reflux column.
Acetic anhydride will be used in this experiment so that when ester is formed, water is not produced. As a result, the thermodynamic equilibrium will now be for the formation of an ester instead of its hydrolysis.
Before proceeding with the experiment you should review several items. First, you should be familiar with the ester functional group. Esters are formed when an acid and an alcohol combine.
You should be able to quickly identify an ester by looking at the structural formula. There are only three types of compounds which have an oxygen located between two carbons. These are ethers, esters and acid anhydrides.Methyl salicylate is an ester easily recognized by its odor and is known as oil of wintergreen because of its natural source.
This ester will be treated with aqueous base. Mar 23, · The purpose of this experiment was to perform a base-catalyzed hydrolysis reaction while converting oil of wintergreen to salicylic acid.
The full balanced molecular equation for the salicylic acid synthesis is C 8 H 8 O 3 + 2 NaOH + H 2 SO 4 -> C 4 H 6 O 3 + Na 2 SO 4 + CH 3 OH + H 2 O. the mechanism for the acid catalysed hydrolysis of esters This page looks in detail at the mechanism for the hydrolysis of esters in the presence of a dilute acid (such as hydrochloric acid or sulphuric acid) acting as the catalyst.
The mechanism is supported by experiments using 18 O labeled compounds and esters of chiral alcohols. This reaction is known as "saponification" because it is the basis of making soap from glycerol triesters in fats. The mechanism is . Alcohol Dehydration of 4-methylpentanol (a)based on the mechanism of the reaction, explain why (E) and (Z) 4-methylpentenes and the 2-methylpentene are the three major alkene products.
(b)Explain why the reaction conditions promote carbocation rearrangements between. Methyl salicylate, for example, is oil of wintergreen, isopentenyl acetate is oil of banana or pear, catalyzed, in this case, by a mineral acid, e.g., sulfuric or phosphoric acids.
In general, the mechanism for esterification follows the Write out the complete reaction mechanism (to include intermediates.