In one swell foop, sync your AD to other domain controllers and Azure. Paste this into administrative Powershell, on the domain controller which does your Azure sync:

repadmin /syncall /AdeP
Import-Module ADSync
Start-ADSyncSyncCycle -PolicyType Initial

And here is the same command set, suitable for a batch file to be run as administrator:

repadmin /syncall /AdeP
@"%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -InputFormat None -ExecutionPolicy Bypass -Command ^
"Import-Module ADSync; Start-ADSyncSyncCycle -PolicyType Initial"

And one more, also a batch file, transmitting only to Azure, without the LAN-LAN AD sync. Needed when the synchronizer is not run on a domain controller:

@"%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe" -NoProfile -InputFormat None -ExecutionPolicy Bypass -Command ^
"Import-Module ADSync; Start-ADSyncSyncCycle -PolicyType Initial"