March 28, 2024, 09:36:01 PM
Forum Rules: Read This Before Posting


Topic: Aspirin sythesis bi product  (Read 5924 times)

0 Members and 1 Guest are viewing this topic.

Offline zilalti

  • Regular Member
  • ***
  • Posts: 46
  • Mole Snacks: +2/-2
  • Gender: Male
  • I'm a mole!
Aspirin sythesis bi product
« on: October 30, 2005, 04:43:28 PM »
I recently synthesised aspirin by refluxing 2-hydroxybenzoic acid with ethanoic anhydride. Then filtering and recrystalizating with HCl I obtained about 1 or 2 grams of the impure aspirin.
Hears my question, when i dried the crystals in the dessicator on filter paper it burnt a hole right through. I know ethanoic acids is a biproduct but surely its not responsible. Anyone know what happened??.
     

Offline movies

  • Organic Minion
  • Retired Staff
  • Sr. Member
  • *
  • Posts: 1973
  • Mole Snacks: +222/-21
  • Gender: Male
  • Better living through chemistry!
Re:Aspirin sythesis bi product
« Reply #1 on: October 30, 2005, 05:02:48 PM »
Sounds like residual HCl to me.

Offline zilalti

  • Regular Member
  • ***
  • Posts: 46
  • Mole Snacks: +2/-2
  • Gender: Male
  • I'm a mole!
Re:Aspirin sythesis bi product
« Reply #2 on: October 30, 2005, 05:35:50 PM »
hmm i suppose but it was a charred hole almost like it had ignited, i would have thought HCl corrosion would look different.

Offline movies

  • Organic Minion
  • Retired Staff
  • Sr. Member
  • *
  • Posts: 1973
  • Mole Snacks: +222/-21
  • Gender: Male
  • Better living through chemistry!
Re:Aspirin sythesis bi product
« Reply #3 on: October 30, 2005, 07:55:36 PM »
Depends on how it happened.  Have you ever seen the demonstration where sulfuric acid is added to table sugar resulting in a column of charcoal?  It looks just like you had burned something, but there isn't any burning, just dehydration of the hydrocarbons.

Offline Mitch

  • General Chemist
  • Administrator
  • Sr. Member
  • *
  • Posts: 5298
  • Mole Snacks: +376/-3
  • Gender: Male
  • "I bring you peace." -Mr. Burns
    • Chemistry Blog
Re:Aspirin sythesis bi product
« Reply #4 on: October 30, 2005, 08:05:26 PM »
isn't any burning, just dehydration of the hydrocarbons.
Specifically oxidation of hydrocarbons for those purest physical organic chemists.
Most Common Suggestions I Make on the Forums.
1. Start by writing a balanced chemical equation.
2. Don't confuse thermodynamic stability with chemical reactivity.
3. Forum Supports LaTex

Offline movies

  • Organic Minion
  • Retired Staff
  • Sr. Member
  • *
  • Posts: 1973
  • Mole Snacks: +222/-21
  • Gender: Male
  • Better living through chemistry!
Re:Aspirin sythesis bi product
« Reply #5 on: October 31, 2005, 01:37:04 AM »
Ah!  Bested by Mitch once again!  ;)

Sponsored Links