• Home
  • About
  • Chemistry
    • Solvent of the Week
    • Compound of the Week
    • Reagent of the week
    • Publications
    • Translations
    • Glassware designs
    • Advanced Preparative Separation
    • Videos
    • A day in a mineral lab
    • A day in a wine lab
    • A day in a polyurethane lab
  • Philosophy
    • Poor Matthew
    • On Australian coins
    • On global warming
    • On aluminium cans
    • Questions to ask potential housemates
    • Why chemistry skills are now less valued than they were
    • Tribute to Mr John Clarke
    • Theory on Covid-19
  • Photos
  • Blog
MJLPHD

On the use and handling of 2-Bromo-2-methylpropionic acid

22/5/2014

0 Comments

 
Picture2-Bromo-2-methylpropionic acid
2-Bromo-2-methylpropionic acid (CAS: 2052-01-9) is a useful reagent to make synthetic intermediates. A white solid at RT, it can be prepared from the acid bromide equivalent reagent, which is known as α-Bromoisobutyryl bromide (liquid at RT) by quenching it with water.
2-Bromo-2-methylpropionic acid can be left over in a workup after doing a reaction using a slight excess of α-bromoisobutyryl bromide, it is easily removed by liquid/liquid extraction with bicarbonate added to the aqueous phase. It can be ordered from Sigma Aldrich for a low price, but it I found it had a shorter shelf life than expected, after 1 year my NMR showed a second similar compound. C-NMR is better to analyze this compound as it gives three distinct peaks, whereas its H-NMR has one good peak but observing the hydroxyl is less reliable. However, I have discovered that it is remarkable easy to kugel rohr this reagent and it should be purified by kugel rohr before use. The compound looks very white and flakey when it is pure, like grated coconut, but after 1 year it has a slight yellow colour and instead of flakes it forms large crystalline shards. It has an acrid smell to it no matter how pure it is.

Picture2-Amino-2-methylpropionic acid and 2-nitro-2-methylpropionic acid
If 2-bromo-2-methylpropionic acid is reacted with an amine to give the amide, the bromo group can then be substituted for a nitro using a Kornblum type reaction with NaNO2 in DMF. I am still pursuing a technique to prepare the nitro equivalent of this reagent, which would be called 2-nitro-2-methylpropionic acid. The amino equivalent exists and is a kind of quasi amino acid, but the nitro version would have the advantage of not being zwitterionic which would make it a more versatile organic soluble reagent. Due to a lack of resources, this project is currently on the back burner.

0 Comments

    Matthew's Chemistry blog.

    A chronicle of tips, tricks & stories

    Contributions from readers are welcome and should be emailed to matthew.leonard742@gmail.com

    Archives

    September 2016
    December 2015
    September 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    May 2014
    March 2014
    February 2014
    January 2014
    December 2013
    November 2013
    October 2013

Powered by Create your own unique website with customizable templates.