Compounds of the formula SPC1 Wherein R1 is alkoxy of 1 to 3 carbon atoms, morpholino, thiomorpholino, 1-oxido-thiomorpholino, 1,1-dioxido-thiomorpholino, or EQU1 where A is hydrogen, alkanoyl of 1 to 4 carbon atoms, alkenoyl of 2 to 4 carbon atoms, methoxy-(alkanoyl of 1 to 4 carbon atoms), carboxyl-(alkanoyl of 1 to 4 carbon atoms), acetyl-(alkanoyl of 1 to 4 carbon atoms), methoxy-(alkenoyl of 2 to 4 carbon atoms), carboxyl-(alkenoyl of 2 to 4 carbon atoms), acetyl-(alkenoyl of 2 to 4 carbon atoms), aminocarbonyl, mono(alkyl of 1 to 4 carbon atoms)-aminocarbonyl, di-(alkyl of 1 to 4 carbon atoms)-aminocarbonyl, methoxymethylaminocarbonyl, pyridinoyl, salicyloyl, furanoyl, or (alkyl of 1 to 3 carbon atoms)-sulfonyl, R2 is morpholino, thiomorpholino, 1-oxido-thiomorpholino, 1,1-dioxido-thiomorpholino, piperazino or N'-[acetyl-(alkanoyl of 1 to 3 arbon atoms)]-piperazino, R3 is hydrogen, chlorine, bromine, nitro, cyano, formyl, acetyl or carbalkoxy of 2 to 4 carbon atoms, and R4 is hydrogen, chlorine, bromine, cyano, carbalkoxy of 2 to 4 carbon atoms, alkyl of 1 to 6 carbon atoms, mono(carbalkoxy of 2 to 4 carbon atoms)-alkyl of 1 to 6 carbon atoms, di(carbalkoxy of 2 to 4 carbon atoms)-alkyl of 1 to 6 carbon atoms, hydroxyl, allyloxy, alkoxy of 1 to 6 carbon atoms, mercapto, allylmercapto, (alkyl of 1 to 6 carbon atoms)-mercapto, 1-oxidothiomorpholino, or where B is hydrogen, alkyl of 1 to 3 carbon atoms, cyclohexyl, phenyl, chloro-phenyl, carboxy-phenyl, carbomethoxy-phenyl or pyridyl, And non-toxic, pharmacologically acceptable acid addition salts thereof; the compounds as well as the salts are useful as antithrombotics.