| abstract |
The present invention provides a compound having a superior acid secretion inhibitory action, an antiulcer activity and the like. n A proton pump inhibitor containing a compound represented by the formula (I) n n n n n n n n n n wherein ring A is a saturated or unsaturated 5- or 6-membered ring group optionally having, as a ring-constituting atom besides carbon atom, 1 to 4 hetero atoms selected from a nitrogen atom, an oxygen atom and a sulfur atom, ring-constituting atoms X 1 and X 2 are each a carbon atom or a nitrogen atom, a ring-constituting atom X 3 is a carbon atom, a nitrogen atom, an oxygen atom or a sulfur atom, R 1 is an optionally substituted aryl group or an optionally substituted heteroaryl group, R 2 is an optionally substituted alkyl group, an optionally substituted aryl group or an optionally substituted heteroaryl group, R 3 is an aminomethyl group optionally substituted by 1 or 2 lower alkyl groups, which is a substituent on a ring-constituting atom other than X 1 , X 2 and X 3 , and ring A optionally further has substituent(s) selected from a lower alkyl group, a halogen atom, a cyano group and an oxo group, or a salt thereof or a prodrug thereof. |