Aspirin Synthesis Sample Prelaboratory
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View Aspirin Synthesis Sample Prelaboratory as PDF for free.
More details
- Words: 457
- Pages: 3
Synthesis of Aspirin Jones:
Esterification, pg 896-904, Figure 18.34
McMurry:
Esterification, pg 317-318, 323
This procedure has been adapted from the microscale procedure described in Experimental Organic Chemistry A Balanced Approach: Macroscale and Microscale by Jerry R. Mohrig, Terrence C. Morrill, Christina Noring Hammond, and Douglas C. Neckers.
Background Salicylic acid is the active ingredient in aspirin that causes pain relief. However this acid is too harsh on the mucous membranes in the mouth, esophagus, and stomach. An acetyl group is added to buffer the effects of the acid. In commercial aspirin there is 0.325 g of acetylsalicylic acid and a binder is used to hold it into tablet form. H
O
O
H O
H
Salicylic acid
O
O O
CH3 O
Acetylsalicylic acid (aspirin)
O
O H 3C
N H
Acetaminophen
H
CH3 CH H 3C C H2
CH3 CH OH O Ibuprofen
Figure 1. Typical analgesics. In this experiment you will continue your study of natural product synthesis by taking your previously synthesized salicylic acid and preparing aspirin. Transformation of the hydroxyl functional group will be achieved by utilizing an esterification reaction, which is the reaction of a carboxylic acid with an alcohol to form a carboxylate ester. You will be using acetic anhydride and salicylic acid as your carboxylic acid and alcohol. This reaction is acid catalyzed using phosphoric acid as the catalyst.
Synthesis of Aspirin 1
H
O
O
O
H O
H
O
+
O
O
O O
H2PO4
O
CH3 CH3 Acetic Anhydride bp 139 o C M.W. 102, d 1.08
Salicylic acid mp 160 oC M.W. 138
CH3
+
Acetylsalicylic acid (aspirin) mp 135136 oC M.W. 180
HO
O CH3
Acetic acid
Figure 2. Balanced equation for the synthesis of aspirin.
H O H
O
H OH2
O O
H
O
O
O
H
protonation acid/base rxn
O
O
H 3C
O O
O O H
OH2
deprotonation acid/base rxn
H 3C
CO2H
H H 3C
O O
O O
CO2H
addition
O O
O O
CH3 protonation acid/base rxn
H OH2
CO2H
CH3 H
H
CO2H
H
CH3
O
CH3 CH3 O
CH3 CH3 H
O
H 3C elimination
O O CO2H
+
H
O
O CH3
Figure 3. Complete mechanism for synthesis of aspirin
Synthesis of Aspirin 2
1. Fill out the following table. Responses must be typewritten. Show all calculations.
Initial Weight of salicylic acid (in g) Initial amount of salicylic acid (in moles) Theoretical yield of aspirin (in moles) Theoretical yield of aspirin (in g) Actual yield of aspirin ( in g) % yield melting point (°C) Make a table for the Observation on the synthesis of aspirin! Saka yung chemical test, iodine test at yung iba pa, FeCl3 yata yun.
Synthesis of Aspirin 3
Esterification, pg 896-904, Figure 18.34
McMurry:
Esterification, pg 317-318, 323
This procedure has been adapted from the microscale procedure described in Experimental Organic Chemistry A Balanced Approach: Macroscale and Microscale by Jerry R. Mohrig, Terrence C. Morrill, Christina Noring Hammond, and Douglas C. Neckers.
Background Salicylic acid is the active ingredient in aspirin that causes pain relief. However this acid is too harsh on the mucous membranes in the mouth, esophagus, and stomach. An acetyl group is added to buffer the effects of the acid. In commercial aspirin there is 0.325 g of acetylsalicylic acid and a binder is used to hold it into tablet form. H
O
O
H O
H
Salicylic acid
O
O O
CH3 O
Acetylsalicylic acid (aspirin)
O
O H 3C
N H
Acetaminophen
H
CH3 CH H 3C C H2
CH3 CH OH O Ibuprofen
Figure 1. Typical analgesics. In this experiment you will continue your study of natural product synthesis by taking your previously synthesized salicylic acid and preparing aspirin. Transformation of the hydroxyl functional group will be achieved by utilizing an esterification reaction, which is the reaction of a carboxylic acid with an alcohol to form a carboxylate ester. You will be using acetic anhydride and salicylic acid as your carboxylic acid and alcohol. This reaction is acid catalyzed using phosphoric acid as the catalyst.
Synthesis of Aspirin 1
H
O
O
O
H O
H
O
+
O
O
O O
H2PO4
O
CH3 CH3 Acetic Anhydride bp 139 o C M.W. 102, d 1.08
Salicylic acid mp 160 oC M.W. 138
CH3
+
Acetylsalicylic acid (aspirin) mp 135136 oC M.W. 180
HO
O CH3
Acetic acid
Figure 2. Balanced equation for the synthesis of aspirin.
H O H
O
H OH2
O O
H
O
O
O
H
protonation acid/base rxn
O
O
H 3C
O O
O O H
OH2
deprotonation acid/base rxn
H 3C
CO2H
H H 3C
O O
O O
CO2H
addition
O O
O O
CH3 protonation acid/base rxn
H OH2
CO2H
CH3 H
H
CO2H
H
CH3
O
CH3 CH3 O
CH3 CH3 H
O
H 3C elimination
O O CO2H
+
H
O
O CH3
Figure 3. Complete mechanism for synthesis of aspirin
Synthesis of Aspirin 2
1. Fill out the following table. Responses must be typewritten. Show all calculations.
Initial Weight of salicylic acid (in g) Initial amount of salicylic acid (in moles) Theoretical yield of aspirin (in moles) Theoretical yield of aspirin (in g) Actual yield of aspirin ( in g) % yield melting point (°C) Make a table for the Observation on the synthesis of aspirin! Saka yung chemical test, iodine test at yung iba pa, FeCl3 yata yun.
Synthesis of Aspirin 3
Related Documents
Aspirin Synthesis Sample Prelaboratory
April 2020 10
Synthesis Paper Sample
April 2020 9
Aspirin
November 2019 16
Synthesis Of Aspirin (2emt - Group 1, 2009)
June 2020 4
Drug Aspirin
May 2020 9
Synthesis
April 2020 44More Documents from "Eileen White"
Realtimeinstructions.pdf
October 2019 8
Uplb Perspective 0809 - 7th Ish
December 2019 22
Builder Detail Flier Final
April 2020 14
Uplb Perspective 0809 Special Election Ish
December 2019 12