Essay #15 Synthesis of Ethyl Salicylate from Salicylic Acid

1555 Words Dec 5th, 2011 7 Pages
#15 Synthesis of Ethyl Salicylate from Salicylic Acid
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Purpose: Salicylic acid is converted to the liquid ethyl salicylate by addition of ethanol.
Yields of salicylic acid (week 1) and ethyl salicylate will be found, as well as the overall yield of the 2-step conversion of acetyl salicylic acid to ethyl salicylate.
Introduction:
Esters are formed from the reaction of acids and alcohols: O O || || R-C-OH + HO-R’ → R-C-OR’ + H2O acid alcohol ester water
The pleasant smelling oil of ethyl salicylate is made by reacting salicylic acid (week 1) with
excess
…show more content…
Record on data sheet and compare with literature values. Part C: Yields
1. The 50 aspirin tablets contained 16.25 g ASA. To estimate yields in your next 2 reactions, assume the wet ASA you used contained 12 g ASA. Then from the mass of dry salicylic acid obtained find the yield of salicylic acid.
2. Convert the volume of ethyl salycilate to grams using the density, 1.1 g/mL. Record.
Estimate yield of ethyl salicylate from salicylic acid and record, retaining just 2 significant figures. 3. Find the overall yield of the two-step process:
Step 1: Acetyl salicylic acid (ASA) to salicylic acid (SA)
Step 2: Salicylic acid (SA) to ethyl salicylate (ES)4
Data and Results (yield of ethyl salicylate)
Name(s) ____________________________________________________________

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Part B: Melting Points
Compound Measured Melting Point (˚C) Literature Value (˚C)
Acetyl Salicylic Acid 134 - 135
Salicylic Acid 158 - 160
Yields:
Assuming ASA (from extraction of 50 aspirin tablets) = 12 g
SA (from hydrolysis of ASA) ______ g
Reactant SA esterified: ______ (usually most of the amount above)
Approximate volume of ethyl salicylate: _______ mL (density ES = 1.1 g/mL)
Mass ethyl salicylate ________g
Maximum g SA:
Maximum g ES: Enter amounts where indicated in the table below and find the yields.
Reaction
Reactant → Product
Mass
Reactant (g)
Mass Product
(g) Maximum
Mass Product
(g) Actual
Yield %
(

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