Boys take longer, if you push it, it will backfire.
Put him back into pullups, then take him to the potty every hour to hour and a half and ask him to at least try.
If he goes, YEAH! If not well then thank him for trying.
Put up a chart, use stickers to chart out how well he does and have a reward he really wants at the end. My daughter potty trained for Care Bears, my son Transformers!
If you push him it will be a power struggle.
He has to fully understand the urge, be able to hold it, wake up dry and all that. If he isn't ready, he isn't ready.
Boys are funny and really just not ready unless all the pieces fit. So give him some time. Take him into the potty frequently but just ask him if he will try.
Don't give up but also don't sweat it either. Don't use diapers, use pullups. I trained both of mine fine in pullups!!! I didn't care for the potty messes and it made the situation harder. I don't believe in putting them in underwear at all until they are really ready, because it stresses you out with the messes and it does them. Tell him very matter of fact, when he is ready to be a big boy, here are the cool underwear he can have!!
My feeling is wait and give it time so when it is done it is done 100%, otherwise you can do what you are doing and it drag out longer and be stressful. Personally for me, just waiting helped.
My daughter and son were 100% (day and night)potty trained shortly after their third bday, it was worth just waiting!!!!