2-(2,5-Dihydroxyphenyl)-2-thiopseudourea monohydrochloride 6274-93-7 NSC33521 Pseudourea, 2-(2,5-dihydroxyphenyl)-2-thio-, hydrochloride Pseudourea, 2-(2,5-dihydroxyphenyl)-2-thio-, monohydrochloride Usaf pd-17 WLN: QR DQ CSYZUM &GH