First try mixing it with food. If he takes apple sauce yet, try that since it masks it well. If he can't eat any solids yet try my next suggestion.
The best option however if that won't work and you don't mind paying for it is to have your medication flavored. Many pharmacies do this including Genuardis, the one I work for in the area. Most meds can be flavored. If you go to a pharmacy and they tell you they can't flavor it this may b/c the pharmacy doesn't want to take the time to do it for you (i've been told about this experience from friends of mine). I can tell you that genuardis definately does it and will even favor meds from other pharmacies as long as you tell them how many doses you have given so far so they can do it correctly. However it is easiest to do it with meds that have not been started yet. The flavors come in everything from classic bubblegum to chocolate cherry pie - why didn't they have this when I was a kid:) Some meds can only be flavored with one flavoring such as zantac b/c it tastes so strong. hope this helps. if you have any questions feel free to contact me.