guanoxan guanoxan guanoxan is a sympatholytic drug that was marketed as envacar by pfizer in the uk to treat high blood pressure. it was not widely used and was eventually withdrawn from the market due to liver toxicity. guanoxanclinical dataatc codec02cc03 (who) identifiers iupac name 2-(2,3-dihydro-1,4-benzodioxin-2-ylmethyl)guanidine cas number2165-19-7 ypubchem cid16564chemspider15704 nunii9v0mrl0r5ycomptox dashboard (epa)dtxsid3046166 chemical and physical dataformulac10h13n3o2molar mass207.233 g·mol−13d model (jsmol)interactive image smiles c1ccc2c(c1)occ(o2)cnc(=n)n inchi inchi=1s/c10h13n3o2/c11-10(12)13-5-7-6-14-8-3-1-2-4-9(8)15-7/h1-4,7h,5-6h2,(h4,11,12,13) nkey:hiuvkvdqfxdzhu-uhfffaoysa-n n ny (what is this?) (verify)