[superg]

Hi,

i'm looking for new lab experiment for organic chem lab course. we tried few thing, working well in the lab but when back to student lab something went wrong almost all times: need high vac to really remove solvents, compound decompose at melting point, reagent too expensive...

do anyone of you know a unmissable organic prep, easy to do and purify compound? also not toxic.

thanks

[azmanam]

dropwise addition of [8 g (~2 eq) oxone in water (1M)] to [cyclohexene (14 mmol) and 3.5 eq bicarb in acetone (0.5 M)] at 0 degC.  stir rt 30 min.  Gravity filter off solids, extract 2x25 mL Et2O, wash 20 mL H2O, dry MgSO4, rotovap off ether to give (meso) cyclohexene oxide as clear yellow oil.  We did conformation by GC/MS and refractive index - your instrument needs may vary.

cyclohexene stinks - have students cap flask during transfer/setup.  need slow, dropwise addition to avoid frothing.  need adequate stirring as solids will settle and inhibit stirbar.  Major product contaminant is water.  Ether layer must be thoroughly dried with MgSO4 before filtering.

When I did it, I got ~80%.  Students don't rinse flasks after transfers, don't wash filter cake to ensure complete transfer, etc... and student yields were typically below 50%, but all students got product.

proc modified from http://dx.doi.org/10.1016/S0040-4039(00)00769-3

[Telamond]

The synthesis of paracetamol is very straightforward and easy.
Synthesized via addition of aceticanhydride to 4-aminophenol in water. Takes 10 min.
Purification via recrystalization and you're done!

Or they could always check how much 1L water weighs...

[superg]

thanks for reply,

the meso cyclohexen oxide might be a good idea, we'll see if it suits to requirement. paracetamol could also be a good idea, but need toxic and corrosive reagents...

thanks for that

if someone else got any idea, please let me know