iPhone disabled - recover data

I've forgotten my passcode and now the phone is disabled and says connect to iTunes. When I connect to iTunes my phone does not appear. All I want to do is to back up the phone. I'm happy to then restore it but I need to back it up before the restore. I know my iCloud and Apple ID passwords but have not backed up to iCloud before, stupidly. Please can anyone help me to back the phone up whilst it is disabled? My phone is full of photos I cannot lose.