The purpose of this experiment was to prepare a benzocaine, by direct Fisher esterification of p-aminobenzoic acid with ethanol in the presence of sulfuric acid as catalyst.
Equations
Percent Yield= (mass product obtained)/(mass therotical ) X 100
Results
Table 1: Percent yield of crude benzocaine, its melting point and comparison with literature value
Melting Point Melting Point Range Percent Yield
82.9 °C – 84.5°C 1.6 59.3% Discussion The weight of the final product was 0.086 grams. The melting point was 82.9 °C – 84.5°C. According to PubChem, the melting point of benzocaine is 92 °C. The reason why the experimental melting point was lower than the literature melting point could because there might have been impurities in the benzocaine that was obtained experimentally. The melting point range was 1.6. The percent yield was 59.3%. …show more content…
A nucleophile is an atom or molecule that wants to donate a pair of electrons. An electrophile is an atom or molecule that wants to accept a pair of electrons. In this reaction, the first thing that happens is the protonation of the carbonyl oxygen activates the carboxylic acid toward nucleophilic attack by alcohol, yielding a tetrahedral intermediate. The nucleophile in this reaction is H2SO4. The electrophile in this reaction is the p-aminobenzoic acid. A transfer of a proton from one oxygen atom to another yields a second tetrahedral intermediate and converts the OH group into a good leaving group. Loss of a proton and expulsion of H2O regenerates the acid catalyst and gives the ester product. In the presence of H2SO4, NH2 forms a
Equations
Percent Yield= (mass product obtained)/(mass therotical ) X 100
Results
Table 1: Percent yield of crude benzocaine, its melting point and comparison with literature value
Melting Point Melting Point Range Percent Yield
82.9 °C – 84.5°C 1.6 59.3% Discussion The weight of the final product was 0.086 grams. The melting point was 82.9 °C – 84.5°C. According to PubChem, the melting point of benzocaine is 92 °C. The reason why the experimental melting point was lower than the literature melting point could because there might have been impurities in the benzocaine that was obtained experimentally. The melting point range was 1.6. The percent yield was 59.3%. …show more content…
A nucleophile is an atom or molecule that wants to donate a pair of electrons. An electrophile is an atom or molecule that wants to accept a pair of electrons. In this reaction, the first thing that happens is the protonation of the carbonyl oxygen activates the carboxylic acid toward nucleophilic attack by alcohol, yielding a tetrahedral intermediate. The nucleophile in this reaction is H2SO4. The electrophile in this reaction is the p-aminobenzoic acid. A transfer of a proton from one oxygen atom to another yields a second tetrahedral intermediate and converts the OH group into a good leaving group. Loss of a proton and expulsion of H2O regenerates the acid catalyst and gives the ester product. In the presence of H2SO4, NH2 forms a