You may want to get a copy of H.H. Karekin I's Council of Chalcedon and the Armenian Church
. It might be out of print right now, but I get the feeling that if you contact the Western Diocese or the Eastern Diocese, one of them should be able to scare up a copy for you.
I haven't looked at my copy recently, but if I recall correctly, His Holiness considered the first council to be a rejection of Chalcedon. Others, though, have named the latter council as the first recorded rejection of it. I think the problem is that Chalcedon was not mentioned by name until the latter council. If I recall correctly, though, the first one is considered by His Holiness to be a rejection of Chalcedon because it was in reaction to the Assyrians saying that the Greeks had just had a council which vindicated their Christology.
Again, I haven't read the book in a long time, so I am working off of my very imperfect memory.