Shulgin makes a lot of that clear in PiHKAL. TMA was his 1st paper on psychedelic use in humans (~1960), but he mentions that it was made by P. Hey at University of Leeds in 1948.
Shulgin made MMDA in 1962 and thought at the time that it was his 1st new creation, but he says that it was also made by Gordon Alles at UCLA the same year. Alles was dead the next year and I think Shulgin said they didn't get a chance to meet.
But I was under the impression that Shulgin created most of the contents of PiHKAL and TiKHAL unless...it was clear that he didn't.
I guess it's not always explicitly stated, but I knew that he didn't create MDMA, LSD of course...mescaline. Without thinking too hard, I'll assume there are a good handful that he didn't create/invent, but for 2ci to be one of those that he did not...that's a big surprise to me.