First, how long is he in there? At 2, he should only be in any kind of "time out" for 2 minutes (one for each year of age.) We have had better luck personally with "time ins", we take a Couch Break when they are getting out of hand or "misbehaving" and we cuddle on the couch until they get it under control and we figure out a solution. If what you're doing isn't having the results you're hoping for, there's no harm in trying a different approach!
That said, here is a good article I found on successful time outs that may help what you're doing to work the way you would like it to.
Copy and paste this link: http://www.dbpeds.org/articles/detail.cfm?TextID=739
at 7:54 PM on Apr. 9, 2009