Hi Anand,
thanks for the quick response now the transfer works 
The changes i made:
dns1:
pattern:
name: “dns2”
notify: 45.xx.yy.195@5353 sec_key
provide-xfr: 45.xx.yy.195 sec_key
dns2:
pattern:
name: “dns1”
allow-notify: 45.xx.yy.194 sec_key
request-xfr: AXFR 45.xx.yy.194@5353 sec_key
Another small thing was the fact that the command nsd-control write always says “ok” but nothing was written!
Turns out that the you have to change the permissions to user “nsd” 
Thanks again everything is working fine now.
Oliver