My daughter stopped napping at 2 1/2 and I was really distraught over it bc my sister said they should nap until 4 - then I talked to a bunch of other moms and found out there are a lot of children who just won't nap at age 2 and 3. There is nothing you can do to make a child sleep if they won't sleep. She is now 3, we just do "quiet time" everyday and start the bedtime process at 6:30. She sleeps until 7-7:30.
Occasionally she will nap, but even after quiet time if we go for a drive she is usually wide awake, which truly lets me know she is over it - that was always a way she would sleep.
It may be a phase and he may start napping again, that sometimes happens, but until you know for sure I would just start bedtime early.