If acylating anilines is what you've tried, maybe you should use an acid chloride!

Hi there.

I know that acylating anilides can be a real pain. All you want to do is a simple Friedel-Crafts reaction, and it just doesn't work. It's that darn amino group. That thing attacks acids like a puppy dog chasing a squirrel. And you don't want to add your acyl group to the amino group, you want to add it to the aromatic ring! What's a fella to do?

Luckily, there is a solution. You can use the amino group's little habit to your advantage. Just feed it a little acid chloride, and it will gobble it right up. That will keep it occupied for a while, but won't change the amino's ortho-para directing powers. With the amino group tied up with the acid chloride, you can acylate the aniline to your liking, and when you're done, just throw in a little acid to hydrolyze the amide and clean up your original amino group.

It's a piece of cake, my friends.