I had no problem booking one way ORD-DOH-SIN in J for Dec. 1 using AA reward for 2 tickets. It showed up on the AA site on Saturday morning at the 331 day mark as the DOH-SIN segment is on Dec. 2. I was able to hold the itinerary on the web.
I called AA and had them book the tickets rather than doing it on the web as I was using miles from two accounts and needed them to link the record locators. No problem. Got my QR record locators and called QR to get my seats EF on Qsuites .