I doubt it.
The problem is pipe diameter, bends, angles, mounting brackets, etc.
IF you have a TiG welder, and you are good with tubing, you could fabricate to adapt.
They make alot of 450 4t motocross exhaust slip-ons.
But those are usually just as expensive, if not more expensive.
And then you would have to try and adapt them to fit properly and not look silly.
If you could get it mounted up good, no reason why it wouldn't work.
450 motocross motors make 55+hp, and turn 12k RPMS.
CBR500 is less HP and less RPMS.
You thinking about trying an FMF or PRO CIRCUIT on there?