Dihydro-1,4-oxazino(2,3-c)quinolines, a process and intermediates for the preparation thereof and their use as medicaments

The present application relates to compounds of the formula I where X is hydrogen, loweralkyl, loweralkoxy, hydroxy, halogen, nitro or trifluoromethyl; R1 is hydrogen or loweralkyl; R2 is hydrogen, loweralkyl, arylloweralkyl or -(CH2)mR7 wherein m is 1, 2 or 3 and R7 is cyano or amino; R3 and R4 are independently hydrogen or loweralkyl; R5 and R6 are independently hydrogen or loweralkyl, or R5+R6 taken together with the carbon atom to which they are attached constitute a cyclobutane, cyclopentane, cyclohexane, cycloheptane, pyrrolidine, piperidine, morpholine or thiomorpholine ring, or R5 is hydrogen and R6 is aryl or -CH2OR8 wherein R8 is hydrogen, loweralkyl or loweralkylcarbonyl, which are useful for enhancing memory. and a process for their preparation. The invention relates also to compounds of the formula II where X, R1 and R3 through R6 are as defined earlier and R9 is hydrogen or bromine (with the proviso that when R1=R3=R4=R5=R6=R9=H, X is not 7-chloro) which are also useful for enhancing memory and for preparing compounds of formula I.