| abstract |
A compound of formula I: ##STR1## wherein either (i) each of R 1 and R 2 independently represents a hydrogen atom or an organic group, or (ii) R 1 and R 2 linked together form a heterocyclic ring or (iii) R 2 is hydrogen and R 1 is ##STR2## wherein each of R 6 and R 7 independently represents hydrogen or an organic group, n is 0-3, X is O, S, NH, NR 8 , CHNO 2 or CHSO 2 R 4 , wherein R 8 and R 4 are organic groups and R 3 represents an organic group. The compound of formula I is effective as an anti-ulcer agent and is highly effective as a histamine H 2 -receptor antagonist. |