| abstract |
Compounds of the formula <IMAGE> wherein R represents substituents of various types; R1 and R2 are each independently hydrogen or lower alkyl; R3 represents substituents of various types; and R4 is hydrogen, alkyl of 1 to 3 carbon atoms, alkoxy of 1 to 3 carbon atoms, halogen, cyano or carbamoyl; tautomers thereof; and non-toxic, pharmacologically acceptable acid addition salts thereof. The compounds as well as their salts are useful as antiulcerogenics. |