The melting point of benzocaine is 8890 c, and the boiling point is about 310 c. Jan 21, 2009 the acid catalyzed esterification done in this experiment is under equilibrium. When benzocaine is applied in any form it temporarily numbs or blocks. Why is the melting point of benzocaine significantly lower than aminobenzoic acid. Metabolism of benzocaine during percutaneous absorption in. How to prepare benzocaine fischer esterification with. Benzocaine bears two functional groups capable of accepting a proton with relative ease, a carbonyl group and an amine group.
Introduction esters are important compounds in organic chemistry. The preparation of the local anesthetic, benzocaine, by an. In this experiment, the synthesis of benzocaine 2 is carried out by the acidcatalyzed esterification of 4aminobenzoic 1 acid with ethanol. Synthesis of benzocaine h2n co2h etoh h2so4 h2n co2et procedure. Microwaveassisted synthesis of local anaesthetic procaine.
They are used in numerous types ofsynthetic reactions, to create different products for a vast array of purposes, including medicinaland cosmetic. The onset of action is rapid benzocaine is most commonly available as a 20% aerosol spray that is easily applied to the oropharyngeal mucosa. This ethyl ester of p aminobenzoic acid paba, a common sunscreen ingredient can react with compounds in sunscreens and hair dyes or produce an allergic reaction. Apply small amount to the penis gland 1520 min before sexual intercourse.
Nh2 is also protonated 2 nucleophillic attack of the alcohol at the carbonyl carbon 3 loss of oxonium leaving group 4 proton transfer leading to a. What do you put in the round bottom flask prior to starting the reaction. Synthesis of procaine february 23, 2016 december 23, 2017 organic put 9. Sciencemadness discussion board synthesis of benzocaine. Auralgan benzocaine and antipyrine is the most commonly prescribed otic drop within shf affected by this decision. The chemistry lab is called, synthesis of benzocaine and it involved the conversion of paminobenzoic acid to benzocaine. Benzocaine was prepared in this experiment by the direct esteri. Immediately start washing your eyes with water and do so for.
A surface anaesthetic, it is used to suppress the gag reflex, and as a lubricant and topical anaesthetic on the larynx, mouth, nasal cavity, respiratory tract, oesophagus, rectum, urinary tract, and vagina. To practice the techniques of refluxing and vacuum filtration to perform an esterification reaction to create benzocaine from paminobenzoic acid. Benzocaine can be prepared by esterification using 4aminobenzoic acid and ethanol. The classic, optimal way of benzocaine synthesis is the reduction of the nitro group of the ethyl ester of 4nitrobenzoic acid to benzocaine by hydrogen, which generates directly in the reaction medium by the reaction of iron filings with dilute acids 2426. Treatment of benzocaine with hydrazine leads to aminostimil a compound related to isoniazid.
In the articles, the only true god and jesus christ whom he hath sent, by jeffery r. Abdelrahman elshamsy april 30 th 2014 the fischer esterification of benzocaine benzocaine is a local anesthetic used in medical applications to reduce pain and increase comfort of painful drugs. The reaction mechanism for the synthesis of benzocaine is divided into six key steps. Synthesis the kingdom of heaven is within the mind of a person, not within the collective mindlessness of a crowd. Metabolism of benzocaine during percutaneous absorption in the hairless guinea pig. Ejectdelay benzocaine dosing, indications, interactions. Benzocaine is an ester of paraaminobenzoic acid, lacking the terminal diethylamino group of procaine, with anesthetic activity. Important key differences between benzocaine and lidocaine. Heat this mixture on a sand bath until all the solid dissolves. Synthesis in a 5ml round bottom flask, add 120 mg of 4aminobenzoic acid often called paba for paminobenzoic acid, 1. Such applications are administered with the leprosy drug, chaulmoogra oil and even reducing the pain from needle injections 4 7.
Synthesis and characterization of benzocaine lessons tes. Sep 06, 2019 how to prepare benzocaine fischer esterification. Using a magnetic stir bar stir the mixture until the solid dissolves completely. Benzocaine is used in multiple forms including lotion, gel, liquid, lozenges, and sprays. Mohannad alashker nathan dyer william cobb dylan davies joe joiner.
Acidcatalyzed ester formation synthesis of benzocaine. Jun 08, 2018 benzocaine is a local anesthetic numbing medication. Students undertake, in a severalweek independent project, the multistep synthesis of a. Benzocaine topical may also be used for purposes not listed in this medication guide. Uses, side effects, interactions, pictures, warnings density calculation. Show the complete reaction mechanism for the synthesis of benzocaine from paba, sulfuric acid and ethanol. A ester of paba and ethanol synthesis of benzocaine. Benzocaine is a waterinsoluble estertype local anesthetic agent that is mainly useful for topical application. Patchoulol or patchouli alcohol c 15 h 26 o is a sesquiterpene alcohol found in patchouli.
Benzocaine topical is used to reduce pain or discomfort caused by minor skin irritations, sore throat, sunburn, vaginal or rectal irritation, ingrown toenails, hemorrhoids, and many other sources of minor pain on a surface of the body. To produce an ester, one can utilize an esterification reaction. To prepare benzocaine a local anesthetic from paminobenzoic acid and ethanol, via a fischer esterification reaction. Benzocaine is a local anesthetic from the ester family. Benzocaine is normally highly soluble in ethanol, but in this experiment sodium carbonate was added in excess and the benzocaine precipitated out of solution. Benzocaine binds to the sodium channel and reversibly stabilizes the neuronal membrane which decreases its permeability to sodium ions. What is the purpose of adding sodium bicarbonate to raise the ph. Benzocaine, a common ingredient in sunburn remedies and first aid creams, is a topical anestheticit numbs the nerve endings near the surface of the skin where it is applied. Benzocaine is a local anesthetic commonly used for pain relief.
Free flashcards to help memorize facts about chm 256 lab final. Benzocaine is a benzoate ester having 4aminobenzoic acid as the acid component and ethanol as the alcohol component. Synthesis of benzocaine quiz synthesis of benzocaine quiz 1. Benzocaine is the ethyl ester of 4aminobenzoic acid 2. List three ways that the equilibrium can be shifted towards the product side of the reaction. So someone that doesnt know better is going to buy some benzocaine off the net and keep on snorting it until they overdose because they read this article that says itll get you high like coke. Patchoulol is also used in the synthesis of the chemotherapy drug taxol. Acetylation of ptoluidine to pmethylacetanilide 7 acetylation is carried out using acetic anhydride in a nucleophilic addition reaction to add an acetyl group c2h3o on to the amine group nh2. Benzocaine is the most popular cutting agent worldwide, benzocaine was used in synthesis of leteprinim. Benzocaine topical should not be used to treat teething pain in infants, and is not approved for use in a child younger than 2 years old. Refer to the structure of procaine in the table in the above introduction, local anesthetics. The drug benzocaine is normally used as a topical pain reliever or as a common ingredient in cough drops. Experiment nine synthesis and purification of benzocaine. Other activities to help include hangman, crossword, word scramble, games, matching, quizes, and tests.
Holland and propaganda under a dictatorship, by aldous huxley are two totally different topics. Currently, seton pharmacies have diminished all inventory of auralgan. How to make anhydrous ethanol 100% alcohol duration. The thing about benzocaine is that while it isnt psychoactive, high enough doses will cause seizures and even death. Dried thoroughly by leaving it in an open container until the next lab, weigh it, calculate the % yield, and determine its melting point. Preparing benzocaine is often done in a school lab setting to demonstrate the acidcatalyzed esterification of a carboxylic. Auralgan and similar products are no longer manufactured and wholesalers no longer stock these products. The ethanol used was denatured, and contained about 90% ethanol by weight. Patchouli oil is an important material in perfumery.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. Use three 1ml portions of cold water to wash the product crystals from the flask onto the funnel. Jul 30, 20 synthesis of benzocaine lab help in this lab we used 4aminobenzoic acid, sulfuric acid, ethanol100%, and sodium bicarbonate. The equilibrium was made to lie far to the right by using acid in excess and carrying out the. There are many brands and forms of benzocaine topical available.
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