There are two male threaded pipe sticking out from the wall for hot and cold water supply in the laundry area. The problem is that those pipe is too close to the benchtop so I want to extend pipe to the below of the benctop so I can install mixer tap on the benchtop instead of wall. I was wondering How can I achieve permanent connection of male to female brass fitting so I don't have to worry about leakage. And the connection will be hidden by installing stud and panel then tiling it for splashback. I am attaching image to explain it better. 
Here I am thinking to join male threaded pipe with female threade compression fitting then joining 15mm copper pipe to another fitting below benchtop. 
So these threaded brass connection with teflon tape and anaerobic sealant 58-11 is reliable to go behind the wall? And compression fitting as well? What would be better option?
