FFMPEG - Creating script to convert a video into audio file (or anything related really) + diverses questions
-vn + -c:v libx264 Does not make any sense. 
This is saying "Don't encode video, but use libx264 to encode no video."

You also can not set a bitrate for wav because it's a noncompressed format.

So your command becomes:

ffmpeg -i name.mov -vn -ar 48000 -ac 2 name.wav