NEW MATERIAL:A compound expressed by formula I [R1 is H, halogen or (F-substituted) lower alkyl; R2 is H, lower alkyl, cycloalkyl, arylalkyl or (substituted) phenyl; R3 is H, lower alkyl, (F-substituted) lower alkoxy, phenoxy, benzyloxy, etc.; X is S or S=O] and salt thereof.
EXAMPLE: 6-Chloro-4-phenylamino-2-(2-pyridylmethylsulfinyl)quinazoline.
USE: A stable medicine and antiulcer agent, having inhibitory action on gastric acid secretion, cytophylactic action and high safety and useful as a preventive and treating agent for gastric and duodenal ulcer, gastritis, etc.
PREPARATION: A 4-amino-2-mercaptoquinazoline derivative expressed by formula II is reacted with a pyridine derivative expressed by formula III (Y is halogen or acid residue of active ester) to provide the compound expressed by formula I (X is S), which is then treated with an oxidizing agent to afford the compound expressed by formula I (X is S=O).
OKUBO AKIHIRO
ISHII KATSUYUKI
ISHIKAWA MIKIO
UEKI SHIGERU
ARAI HEIHACHIRO
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