Ditto Carolyn G.
At this age, many times, a child gets hiccups in their sleep. It's all developmental based.
At each age juncture, this can happen.
Both my kids went through this too, at about the same age and at about 1 years old as well.
It is a phase and will pass. BUT keep to your regular routines of nap and bedtime, and your SAME pre-nap and pre-bedtime routines. Consistency is important.
When he wakes in the middle of the night.... just keep things "boring"...ie: don't turn on any lights, don't "wake" fully... just repetitiously say "sleep..." just let him be unless he is crying or distraught, keep things mellow and quiet.
Its "growing pains" which is not easy for them either, and not easy for us either. But, "sleep" is NOT static in kids anyway... and for various developmental phases, it does change, even if temporarily.
Next, there will be wakings due to night-mares, teething, separation anxiety (which still does occur), and them just being lonely at night and wanting to be near you.
He DOES still need a nap... but "over-tired" kids actually have a harder time sleeping and wake more. He's "cranky" because he is actually tired. But kids don't have the ability to think ahead at this age, and so they won't "know" that they NEED a nap.
Also as they hit "milestones" they often get tweaked in their sleep too.
My son, is 2.5 years old too, and he still naps sometimes twice a day... but at night, he NEEDS to "un-wind" before bed... and he has a routine to un-wind which can take at least 1/2 hour. We just make things quiet and dark, turning off the lights, and keeping things mellow.... and then he likes to turn off the lights himself, and have his own flashlight... and then he plays with it and tosses and turns...then he falls asleep. If need be, then I also lay with him.
No, he is not ready to give up his naps. This is just a phase. For naps, you need to go day by day... I don't believe in taking it away COMPLETELY... yet. At this age, they still need it. So you have to gauge him and observe his cues. A toddler isn't just going to tell us "Mommy I'm going to nap now..." and then do so. At least try and get him to nap one time during the day, even if the timing of it may vary from your normal nap time.
My son, will not last or be "happy" if he does not nap. And he actually gets more "hyper" without proper sleep or naps. "Over-tired" kids sometimes actually do get more hyper the more tired they are. So, I still put him down for naps and sleep as consistently as possible.
It just takes time. He's normal. BUT, I would not turn it into a "battle." It can be repetitive, but it will pass.
All the best,
Susan