benzylthiouracil benzylthiouracil benzylthiouracil (btu) is an antithyroid preparation. it is a thioamide, closely related to propylthiouracil. benzylthiouracilclinical dataahfs/drugs.cominternational drug namesroutes ofadministrationoralatc codeh03ba03 (who) pharmacokinetic dataexcretionrenalidentifiers iupac name 1-(1-cyclohexa-2,4-dienylmethyl)-7-thia-3,5-diazabicyclohepta-3,5-dien-2-one cas number6336-50-1 ypubchem cid685814chemspider597542 yuniipz35lum333chemblchembl1491306comptox dashboard (epa)dtxsid30873587 echa infocard100.026.106 chemical and physical dataformulac11h10n2osmolar mass218.27 g·mol−13d model (jsmol)interactive image smiles s=c1n/c(=c\c(=o)n1)cc2ccccc2 inchi inchi=1s/c11h10n2os/c14-10-7-9(12-11(15)13-10)6-8-4-2-1-3-5-8/h1-5,7h,6h2,(h2,12,13,14,15) ykey:pnxbxcrwxnesov-uhfffaoysa-n y (verify) adverse effects benzylthiouracil has been associated with severe adverse effects, notably vasculitis and subsequent anca-positive glomerulonephritis, as well as isolated reports of lung damage.