One can't make this shit up.. Karlsruhe-based family-run abcr GmbH offering the 3-Hydroxy-1-methyl-5,6-indolinedione (Adrenochrome) for anyone to buy.. The prices are quite substantial..
https://abcr.com/de_en/ab135895
If you enter the CAS 54-06-8 code in the search results, you can find more companies dealing with this substance..
Merck owned Sigma-Aldrich, now MilliporeSigma https://www.sigmaaldrich.com/catalog/product/sigma/a5752?lang=en®ion=SK&cm_sp=Insite--caSrpResults_srpRecs_srpModel_54-06-8--srpRecs3-1
Biosynth (Swiss) + Carbosynth (UK) https://www.carbosynth.com/carbosynth/website.nsf/(w-productdisplay)/96D64C7954A994A5802579CF006191E2
Bocsci - BOC Sciences (USA) https://www.bocsci.com/phenylephrine-impurity-1-cas-54-06-8-item-331586.html
Pharmaaffiliates (India) https://www.pharmaffiliates.com/en/54-06-8-adrenochrome-pa2834520.html
Short squeeze!