Definitely not the right time of year to move any tree, let alone a willow. It is dying of thirst. Dig a trench round it and keep it filled with water. You might have to keep this up right unto the leaves have fallen, then hope that it comes back next spring.

Thank you for reply.
Should I cut it right back to remove all the dead leaves.

Yes....doesn't mind being cut back. As mentioned, willows hate dry so get bucket fulls of water onto the roots

If, by 'dappled willow' you mean Salix hakuro-nishiki, or flamingo willow, many of these are sold as standards, meaning the plant is grafted on top of a straight stem. If that's what yours is, do not cut past the graft on the top of the stem.

I think so I brought it about 8 years ago looks like a tree. Every year I prune it back and it has developed into a lovely looking tree, well until now :-(