Taken from this answer, you can use global-set-key like this

(global-set-key (kbd "C-`") (kbd "<escape>")) 

Which will treat C-` as escape

This does seem to have some problems though if the second combination doesn't execute a function. So if escape is being used like Meta, then it doesn't work correctly. But it seems to work for commands bound to functions.

Taken from this answer, you can use global-set-key like this

(global-set-key (kbd "C-`") (kbd "<escape>")) 

Which will treat C-` as escape

This does seem to have some problems though if the second combination doesn't execute a function. So if escape is being used like Meta, then it doesn't work correctly. But it seems to work for commands bound to functions.

Taken from this answer, you can use global-set-key like this

(global-set-key (kbd "C-`") (kbd "<escape>")) 

Which will treat C-` as escape

Taken from this answer, you can use global-set-key like this

(global-set-key (kbd "C-`") (kbd "<escape>")) 

Which will treat C-` as escape

This does seem to have some problems though if the second combination doesn't execute a function. So if escape is being used like Meta, then it doesn't work correctly. But it seems to work for commands bound to functions.