add a little bit more water and reflux it. 250C sounds pretty excessive, try to stay ~100. you may have fried your mix and will probably need to start over, refluxing is the easiest way to go with a small rxn like that IMHO
Do you think adding more I2 would help if no traces can be seen in the flask??
it it was all sublimed, then you would need fresh stuff. BUT the E is probably toasted...you could try putting new I2, add a little water and just cook/reflux it at about 100C for however long you want- longer is better. you may or may not get anything, depending on how much E survived. the only thing thats probably still alright is the RP. check out some of the links in the 'Stimulants FAQ' for more info