1H-Purine-2,6-dione, 3,7-dihydro-1,3-dimethyl-8-(2-methylpropyl)- (9CI) 4-26-00-02479 (Beilstein Handbook Reference) 5770-30-9 8-Isobutyl theophylline BRN 0235781 NSC 101801 Theophylline, 8-isobutyl- Xanthine, 1,3-dimethyl-8-isobutyl-