Water in window well flooding basement
Your window well should already have a drain that ties into the drain tiles around your foundation. This is likely already tied into your sump. Often over time the drains get clogged up and filled with debris. 

The solution is to dig out the window well and unclog the drain. You should have about a foot of crushed gravel that stops 6" below the window level so that water does not pool on the surface. 

It's also possible the drain has collapsed or been clogged with roots. You would need to first find the drain (dig it out) and then do a video inspection of it to confirm or deny this.