Organic Chemistry II Lab

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Organic Chemistry II - Lab
Labs 7 and 8 Synthesis of Lidocaine
A crystalline solid usually administered as an
aqueous solution of the hydrochloride salt as a
local anesthetic.
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Structure/Activity Relationships
natural product
synthesized
structural components
aromatic
hydrocarbon
carbonyl
amine
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Synthetic Scheme
Two-step synthesis of lidocaine
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Synthesis Step 1
Step 1 - formation of a solid amide by NAS
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Chemistry of Carboxylic Acids Derivatives
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Organic Chemistry II - Lab
Labs 7 and 8 Synthesis of Lidocaine
Week 2
7
Synthetic Scheme
Two-step synthesis of lidocaine


nucleophilic acyl substitution
versus
SN2
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Reaction Scheme Step 2
Step 2 - formation of lidocaine by an SN2
reaction
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Calculation of Et2NH Required
Use 3 moles diethylamine per 1 mole of
a-chloro-2,6-dimethylacetanilide
g acetanilide 3
moles Et2NH 73.14 g/mol Et2NH 197.66
g/mol acetanilide 1 mole acetanilide
0.71 g/mL Et2NH
X
X
Volume of Et2NH required should be 0.1-0.6 mL .
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Procedural Points
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Isolation of Lidocaine Product
Acid extraction is used to remove lidocaine from
the toluene solution