Sounds like it should work fine as long as you don't Jaunt until he casts Imprisonment.
However, since you are dueling and since jaunt has limited duration he might just wait you out. Depends on whether the DM allows him a spellcraft check to differentiate between Invisibility and Jaunt (he won't see the casting since it is contingency activated). I am assuming he does not have a permanent See Invisibility.
If he readies an action to strike at you if you appear next to him what is your plan? If you appear some distance away he can charge and attack. What then?
However, since you are dueling and since jaunt has limited duration he might just wait you out. Depends on whether the DM allows him a spellcraft check to differentiate between Invisibility and Jaunt (he won't see the casting since it is contingency activated). I am assuming he does not have a permanent See Invisibility.
If he readies an action to strike at you if you appear next to him what is your plan? If you appear some distance away he can charge and attack. What then?