| abstract |
A compound of formula I: <IMAGE> wherein either (i) each of R1 and R2 independently represents a hydrogen atom or an organic group, or (ii) R1 and R2 linked together form a heterocyclic ring or (iii) R2 is hydrogen and R1 is <IMAGE> wherein each of R6 and R7 independently represents hydrogen or an organic group, n is 0-3, X is O, S, NH, NR8, CHNO2 or CHSO2R4, wherein R8 and R4 are organic groups and R3 represents an organic group. The compound of formula I is effective as an anti-ulcer agent and is highly effective as a histamine H2-receptor antagonist. |