@ankara-- It can be very difficult to give babies liquid amoxicillin. What flavor do you have?
The pharmacist can add different flavors to it so that babies and kids will take it more easily. You might want to ask for a different flavor if your son hates the one you have now.
When I had to give my daughter liquid amoxicillin, I would give her a toy to distract her or make faces or something and slowly put it in her mouth. Using a clean syringe can make that easier.