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Mutli step synthesis

Synthesis of sulfanilamide

Objective

In this lab we will synthesize sulfanilamide starting with aniline. Our synthetic steps will include a protection of an amine, followed by chlorosulfonylation of the protected aniline. This compound is then deprotected and converted to our target molecule, sulfanilamide, in one final step.

Grading

You will be assessed on:

  • Write-up in your Lab Notebook
  • TA evaluation of lab procedure
  • Answers to Post Lab questions

Introduction

Sulfa drugs have been a very integral part of our medical history. Sulfa drugs were first used in the 1930’s, and are now the oldest antibiotics available and also among the best. Sulfa compounds work by inhibiting nucleic acid (DNA, RNA) synthesis. The way sulfa compounds work is by shutting down the system by which bacteria synthesize their folic acid. They do this by competing with para-aminobenzoic acid (PABA, necessary for folic acid synthesis). See Figure 1 to see if you can tell why sulfanilamide is a competitor for PABA.

Experimental

1. Place 5mL conical vial, Claisen head,½dram vial, and a drying tube packed with glass wool and calcium chloride into the oven for 30 minutes at 125 ° C size 12{°C} {} . 2. Remove glassware from oven and allow it to cool.3. Measure out 230 μL size 12{μL} {} of aniline and 500 μL size 12{μL} {} of methylene chloride to the 5mL conical vial. 4. Immediately place the Claisen head equipped with a septum cap and the drying tube to the vial.5. Place the setup in an ice bath to cool the reagents before adding trifluoroacetic acid. 6. Once the reagents are cool (5 minutes), add 500 μL size 12{μL} {} of methylene chloride to a½dram vial. To this then add 500 μL size 12{μL} {} of trifluoroacetic acid. Draw up the 1 mL total of solution into a syringe and add it through the septum dropwise to the aniline solution.Note: The reaction is exothermic, if the addition is too rapid, the methylene chloride will evaporate. 7. After the addition is complete, let reaction stand at room temperature for 10 minutes.8. After reaction is at room temperature, remove the claisen head and remove methylene chloride by passing air over the top of the solution. This will evaporate the methylene chloride and residual trifluoroacetic acid, leaving the product as a white powder.

Next

1. Place an air condenser and a 9-in Pasteur pipet calibrated to deliver 0.9 mL, into the oven for 30 minutes at 125 ° C size 12{°C} {} .2. Remove glassware from oven and allow it to cool.3. Attach the vial containing 2,2,2-trifluoracetanilide to the dry air condenser.4. Measure out 0.9 mL of chlorosulfonic acid with the pipet and slowly add it to the vial by inserting the pipet down the air condenser.5. Place vial with condenser attached into a sand bath and heat for 10 min. at 65 ° C size 12{°C} {} .6. Collect the precipitate by vacuum filtration and wash with three 1-mL portions of cold water.7. Let the product air dry. Determine the melting point and overall yield.8. Weigh out 400 mg of the p-(2,2,2-trifluoroacetamido)benzenesulfonyl chloride into a 10-mL Erlenmeyer flask.9. In a test tube measure out 0.6 mL of concentrated ammonium hydroxide and 0.4 mL deionized water.10. Add the ammonium hydroxide solution to the Erlenmeyer containing the p-(2,2,2-trifluoroacetamido)benzenesulfonyl chloride. Use a glass stirring rod to break up any chunks that form.11. Add a boiling stone to the Erlenmeyer flask and place the reaction mixture into a sand bath. Heat the reaction to boiling and watch for all the solid to dissolve. Once total dissolution has occurred boil the mixture for an additional minute.12. Once reaction is complete remove the flask from the sand bath and allow to cool to room temperature. Once this is done place the flask into an ice bath for 15 min.13. Collect the yellow crystals that precipitate out of solution and isolate them via vacuum filtration. Wash with three 0.5 mL portions of water to remove any soluble impurities.14. Let the product air dry. Determine the melting point and overall yield.

Post-lab questions:

1. Who won the Nobel Prize for the discovery of sulfanilamide drugs?

2. To give you a better idea of the massive amount and diversity of protecting groups, assign structures to the following list of protecting group abbreviations:AcAdBnBOCCbzFmocMEMONBPptTBDMSTfTHPTIPSTMSTos

A good ref. Protective Groups in Organic Synthesis by Theodora W. Greene3. How do sulfa drugs work?

4. Draw a mechanistic scheme for all reactions done in this lab. (Show correct arrow pushing, and mechanistic detail.)

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
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Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
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Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
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Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
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absolutely yes
Daniel
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it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
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SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
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Source:  OpenStax, Chem 215 spring08. OpenStax CNX. Mar 21, 2008 Download for free at http://cnx.org/content/col10496/1.8
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