ANSWER:

What you are doing is absolutely not permissible and missing fard salah deliberately is a major sin! 

Let him cry all he wants, put toys in front of him to keep him busy. If you give in to his tantrums like this he will never learn to accept no for an answer. 

And besides, do you not go to answer the call of nature for fear of his crying? Set your priorities right and make your life revolve around this obligatory act. 

I am a mother of 4 months old. Most of the time i miss my obligatory prayers due to my son’s crying. He hardly stays quiet on bed. If i leave him crying on the top of his voice & pray, that too is not worth as my whole attention will be towards my crying son. I am afraid for the punishment that i will get bcz of neglecting my prayers. I don’t know what to do.