Chemical Forums

Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: julianm on May 16, 2009, 06:48:15 AM

Title: Your top 3 organic preps??
Post by: julianm on May 16, 2009, 06:48:15 AM
 I do hope you don`t mind a first post being a survey of your combined  favourites!

I`m looking for 3 absolute bankers of 5-10g scale organic preps. Hopefully they will require a range of simpler techniques, and the products will probably be 2 solids & one liquid. No requirement for too long in reflux, stirrers or fume cupboards, just safe, effective preps suitable for 17 yr old students as an introduction to the genre.  Some different techniques, a small range of functional groups & chance for some discussion about mechanisms on a simple level would be perfect.
 I`m returning to this as a teacher after something of a break & have limited time. My previous experience of say the old A level practical exams has one memory of some beautiful yellow needle-like crystals? - can`t recall what they were, however!
 I suspect benzoic acid might be a good option for one of the 3.
So, for some lovely fluffy white solids, fruity liquid & no miserable dregs of greyish sludge, what should I be trying?
 Many thanks in advance for any offers, your help would be much appreciated!
Julian
Title: Re: Your top 3 organic preps??
Post by: StarvinMarvin on May 16, 2009, 07:11:39 AM
Making aspirin is very nice :) It's a simple reaction where nothing can go wrong.

Title: Re: Your top 3 organic preps??
Post by: azmanam on May 16, 2009, 08:39:26 AM
banana oil (isoamyl acetate)
Title: Re: Your top 3 organic preps??
Post by: nj_bartel on May 16, 2009, 01:29:20 PM
banana oil (isoamyl acetate)

Was going to suggest the same thing.
Title: Re: Your top 3 organic preps??
Post by: dougdela on May 17, 2009, 09:25:50 AM
You can do an "overnight" ester prep that my classes find interesting. Look around for an old bottle of Anthranilic acid (it may be a controlled substance now if you buy it new). It gives an interesting twist on a standard prep of methyl salicylate.
The details (even if you don't have the old stuff) can be found here:
http://www.dougdelamatter.com/website/science/chemistry/demos/7-nose.htm

Best of luck, but TRY IT YOURSELF first before you decide on your classroom (safety) procedures.

Title: Re: Your top 3 organic preps??
Post by: julianm on May 17, 2009, 03:32:13 PM
 Thanks very much for the replies! I had thought of the aspirin but a range of esters for a class would make a great variety show - I`ll have a run through & check out the hazards carefully....
 Very apprecuiative of your help - I`ll send my students here as well!
 Julian
Title: Re: Your top 3 organic preps??
Post by: leaftye on May 19, 2009, 12:44:02 AM
I liked the banana oil experiment, but at least one of the girls wasn't crazy about it.  She's allergic to bees and another underlying medical condition could result in death.  She looks perfectly healthy, but it may be something to think about, especially since bees are out and about right now.
Title: Re: Your top 3 organic preps??
Post by: alchmx on May 20, 2009, 03:07:38 PM
Making wintergreen is very easy, methyl ester of salicylic acid, catalyzed by a drop of sulfuric acid. Makes nice crytals, won't kill anyone either. Don't make soap via saponification of fatty esters, no student will use their soap and there will be lots to dispose of later.
Title: Re: Your top 3 organic preps??
Post by: Borek on May 20, 2009, 03:47:34 PM
From other place:

Quote
I like "luminol" (and so do the students). My 2nd favorite is "fluorescein" followed by "ethyrosin".  The latter 2   are graded, in part, on neatness.