NEW MATERIAL:A compound expressed by formulaI[A is a group expressed by formula II or III; R1 is=N-CN or =N-CONH2; R2 is -NH-R3 (R3 is H, alkyl or cyclohexyl)]and an acid addition salt thereof.

EXAMPLE: N-Methyl-N'-cyano-3-(o-chlorophenyl)-2-propenylamidine.

USE: A gastric juice secretion inhibitor exhibiting improved activity, administrable by either one of the oral and parenteral routes, and formulated by an ordinary method into any dosage form.

PROCESS: A 3-substituted 2-propenenitrile expressed by the formula A-CH=CH-CN is subjected to the Pinner reaction or reacted with an alcohol in the presence of a basic catalyst to give an imino ether expressed by formula IV (R is lower alkyl), which is then reacted with cyanamide and an amine expressed by the formula HR2 or the reaction product is further reacted with hydrochloric acid to afford the compound expressed by formulaI.