Do what ^ said, but I'm gonna assume you're recording from the master, or maybe both the drums and synth are linked to insert 1. They need to be separate. You can just mute the drums when you're recording the synth. (I don't really know what you mean by "recording" here, are you recording to piano roll with a midi controller?).
Also, don't use drum patterns. I recommend always using piano roll. Just place the note on C5, that's the equivalent of a drum pattern note.
You need to get used to the piano roll, playlist and mixer.