Nitrobenzoate

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Abstract:
In this experiment, the methyl nitrobenzoate was prepared from methyl benzoate, concentrated HNO3, and concentrated H2SO4 via an electrophilic aromatic substitution reaction. The HNO3 and H2SO4 were combined to form a nitrating solution, which was mixed with a mixture of methyl benzoate and H2SO4. Percent yield for the final product was calculated followed by recrystallization and melting point was measured.

Introduction:
Nitration of Methyl Benzoate is one of the examples of Electrophilic aromatic substitutions. The use of a mixture of Sulfuric Acid and Nitric Acid is the classic way to make NO2+. The two main reaction types used for this are both substitutions: Electrophilic Aromatic Substitution and Nucleophile Aromatic Substitution. The benzene ring itself is electron-rich, which makes Nucleophile Aromatic Substitution difficult, unless there are a number of strongly electron-withdrawing substituents on the ring. EAS, on the other hand, is a very useful method for putting many different substituents on a benzene ring, even if there are other substituents already present.

In this experiment you will put a nitro (—NO2) group on a benzene ring, which already has an OCH3 group, attached to the methyl benzoate.
Reaction:

Procedure: reference to: Lab manual Exp 43 “Nitration of Methyl Benzoate” page 338-341
Results:
* Weight of methyl benzoate: 3.065g
* Weight of methyl m-nitrobenzoate: 3.3443g
Percentage yield of methyl m-nitrobenzoate: 112.3%
*

Calculation:

%yield= (weight of methyl m-nitrobenzoate)/ (weight of methyl benzoate) X 100%
= (3.443g) / (3.065g)X100%
= 112.3%
* Melting point range of product: 1st time: 62oC- 72 oC
2nd time: 68oC- 72 oC

* Theoretically melting point of methyl m-nitrobenzoate: 78 oC Analysis:
From the results we could see, the weight of...
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