BobVila.com

Drywall to Brick

I think that the DW is already up so the J bead would not work.

There are lot of options, but a lot depends on how tight he want to get it and how flat the brick is.

If the brick is irregular and wants a tight fit then it needs to be scribed or maybe a flexable tear away L bead.

Shoe molding could be used. It would not stick out as much as the 1/4 round.

If the DW is not up & the brick is reasonably straight then the J bead is the best and it is commonly available

But get some wide masking tape and put it on the brick first. You can put if off afterwards. If you get caulk, mud, or paint on the brick it will show.

And hopefully the bead will be tight enough to the brick.

I don't like to caulk in cases like this.

But if needed apply new masking tape on the brick so that it is outside the caulkline. And work it down tight as you can get it. Then apply a CLEAR caulk. Use it lightly, but any caulk that gets under the edge of the tape will be clear and not show as bad as white.

Then you can apply more to form a nice bead if you are going to paint it. Or white caulk.

It the DW is already up then you can use an L bead that you can slip the leg between the DW and the brick.

http://www.trim-tex.com/j&lbeads.htm
(Near the bottom)

And you can get them with tearaway beads that act as a mask.

And you can get flexible (archway) ones for use help it fit a little better to brick that is not flat.

But you will have to go to an DW supply house to get something like that and I don't know if they will sell just one or two pieces.