1,3-Dimethyl-8-ethylxanthine 7-oxide 14305-94-3 5-26-14-00180 (Beilstein Handbook Reference) 8-Aethyl-8H-theophyllin-7-N-oxid [German] 8-Ethyltheophylline 7-oxide BRN 0542433 GD 405 Theophylline, 8-ethyl-, 7-oxide