Ethyl Benzoate and Benzyl Benzoate
Ethyl benzoate and benzyl benzoate are important esters of benzoic acid. These compounds are widely used in the pharmaceutical and cosmetic industries. Below is a simple and easy-to-understand explanation useful for Pharm.D students.
1. Ethyl Benzoate
Formula:
C9H10O2
Preparation:
Ethyl benzoate is prepared by treating ethyl alcohol with benzoic acid in the presence of a strong acid such as sulfuric acid (H2SO4). This is a standard esterification reaction.
Test for Purity:
The purity tests are the same as those used for benzyl benzoate.
Assay:
The assay method is also identical to that of benzyl benzoate.
Uses:
- Used as an artificial fruit-flavoring agent.
- Acts as an antifungal preservative in formulations.
2. Benzyl Benzoate
Formula:
C14H12O2
Preparation:
Benzyl benzoate is prepared by the esterification of benzyl alcohol with benzoic acid using a catalyst.
Test for Purity:
This test mainly checks whether the ester group gets hydrolysed to benzoic acid.
Purity checks include:
- Acidity test: Performed using NaOH or sodium bicarbonate.
- Effervescence test: Checked using pH paper.
Assay:
The purity of benzyl benzoate is estimated by saponification. In this test, the ester is reacted with NaOH, and the remaining unreacted NaOH is back-titrated using HCl. The amount of NaOH consumed tells us how much ester was present.
Uses:
- Used as an antiparasitic agent (topical scabicide).
- Used in veterinary practice as an acaricide, pediculicide, and scabicide.
- Acts as a repellent against ticks, mites, chiggers, and mosquitoes.
- Commonly used as an inexpensive and effective treatment for human scabies.
Detailed Notes:
For PDF style full-color notes, open the complete study material below:
PATH: PHARMD/PHARMD NOTES/ PHARMD FIRST YEAR NOTES/ ORGANIC CHEMISTRY/ PHARMACEUTICAL ORGANIC CHEMISTRY/ ETHYL BENZOATE AND BENZYL BENZOATE.