6-Thio-[8-(.beta.-N-pyrrolidinoethyl)thio]theophylline 6559-86-0 NSC99657 Theophylline, 8-[(2-pyrrolidinoethyl)thio]-6-thio- Theophylline, 8-[[2-(1-pyrrolidinyl)ethyl]thio]-6-thio- Uric acid, 1,3-dimethyl-8-[(2-pyrrolidinoethyl)thio]-6-thio-