[Ingeniosuccinimide]

I'm running a reaction which involves use of 18-crown-6 ether and potassium phthalimide, and the crude I isolated contains peaks of these and possibly something new.

When I develop the TLC of the crude, I have the problem that both potassium phthalimide and crown ether are not UV active. Which dip could I use to visualize these two? KMnO4 did not help and we have no iodine at the moment. What about vanilin, anisaldehyde or sth else?

[discodermolide]

A lab with no iodine!!!!
Use anisaldehyde instead.

[salteen]

You could also try ceric ammonium molybdate (CAM).  I've never tried it for a pthalamide or crown ether but in my experience it stains almost everything.

[Arkcon]

I suppose the simplest answer will work too -- expose to sulfuric acid  then heat.  Any organic material will char, and you'll get to visualize the separation.  Useless if you have to isolate spots for later analysis, but you can always do multiple spots, shield some from the acid, char flanking lanes, then excise the non-reacted spots by their position.

[Babcock_Hall]

Phosphomolybdic acid and sometimes ferric chloride/sulfosalicylic acid stain a variety of compounds.