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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Tiffanylight on April 02, 2012, 08:30:08 PM

Title: Basic Mechanism
Post by: Tiffanylight on April 02, 2012, 08:30:08 PM: I am a pharmacy undergraduate and I have been asked to carry out a chemistry based project which I have been finding quite difficult. My knowledge of chemical mechanisms was last update 5 years ago! I have this due in very soon and was looking for some help with the following reaction sequence. I wish to explain in terms of reactive groups and what significance each reactant has. My aim is to write it as a chemical journal style purely for the benefit of my methods and results section. The theory behind this synthesis and what it represents is mainly therapeutic based.

I would really appreciate some in put!!

1. Triethyleneglycol+ in dry pyridine at 0 degrees, TsCl added in portions = 2-[2-(2-Hydroxyethoxy)ethoxy]ethyl 4-methylbenzenesulfonate

2. 2-[2-(2-Hydroxyethoxy)ethoxy]ethyl 4-methylbenzenesulfonate+potassium pthalimide in DMF at 90 degress for 2 hours = 2-{2-[2-(2-Hydroxy-ethoxy)-ethoxy]-ethyl}-isoindole-1,3-dione

3. 2-{2-[2-(2-Hydroxy-ethoxy)-ethoxy]-ethyl}-isoindole-1,3-dione + jones oxidation CrO3. H2SO4 0degrees = {2-[2-(1,3-Dioxo-1,3-dihydro-2H-isoindol-2yl)ethoxy]ethoxy}acetic acid

4.{2-[2-(1,3-Dioxo-1,3-dihydro-2H-isoindol-2yl)ethoxy]ethoxy}acetic acid + hydrazine monohydrate in EtOH, reflux for 20hours=[2-(2-Aminoethoxy)ethoxy]acetic acid
Title: Re: Basic Mechanism
Post by: Dan on April 03, 2012, 03:20:07 AM: You must show your attempt, this is a Forum Rule (http://www.chemicalforums.com/index.php?topic=33740.0).

Look up the reagents in any organic chemistry text book and see what you can come up with.
Title: Re: Basic Mechanism
Post by: AWK on April 03, 2012, 04:06:55 AM: You have rather complicated structures, but your reactions are quite simple. Any good textbook contains mechanism of the following reactions:
1. partial esterification
2. amination of ester
3. oxidation of alcohol
Title: Re: Basic Mechanism
Post by: Dan on April 03, 2012, 04:22:18 AM: Also: Gabriel synthesis
Title: Re: Basic Mechanism
Post by: Tiffanylight on April 03, 2012, 06:06:21 PM: Thanks for the help guys! Great starting point for me.

One question, does Gabriel synthesis still apply as its not an alkyl halide we are dealing with? (It's the tosyl group?)
Title: Re: Basic Mechanism
Post by: Tiffanylight on April 03, 2012, 07:39:02 PM: Or were you referring to the last step? i.e. deprotonation of the phthalimide to get the primary amine?
Title: Re: Basic Mechanism
Post by: Dan on April 04, 2012, 03:14:35 AM: I would still call it a Gabriel synthesis, tosylate is just another good leaving group - the reaction is conceptually exactly the same.