Hetaryloxy-.beta.-carbolines, and use as pharmaceutical agents for treating epilepsy and anxiety

A compound of formula I ##STR17## in which R.sup.A is an isoquinoline, quenoline, or quinoxaline, each optionally substituted with 1 or 2 of halogen, C.sub.1-6 alkyl, C.sub.1-6 alkoxy, C.sub.1-6 alkylthio, trifluoromethyl or SO.sub.2 --R.sup.1,

• R.sup.1 is C.sub.1-4 alkyl or phenyl optionally substituted 1-2 times with C.sub.1-4 alkyl,
• wherein the substituent on R.sup.A is not halogen when R.sup.A is pyridine,
• R.sup.4 is hydrogen, C.sub.1-6 alkyl, C.sub.1-6 alkoxy-C.sub.1-2 alkyl,
• R.sup.3 is --CO.sub.2 --C.sub.1-6 alkyl, --CO-R.sup.2, --CO.sub.2 H, ##STR18## and R.sup.2 is C.sub.1-4 alkyl, C.sub.3-7 cycloalkyl, C.sub.7-9 bicycloalkyl or a monocyclic or bicyclic C.sub.6-12 aryl radical optionally substituted with C.sub.1-4 alkyl, C.sub.1-4 alkoxy or amino,
• R.sup.a and R.sup.b are the same or different and each is hydrogen, C.sub.1-6 alkoxy, C.sub.1-6 alkyl, --CH.sub.2 --C.sub.1-4 alkyl, phenyl or benzyl,
• R.sup.c and R.sup.d each is hydrogen or together form a bond and
• R.sup.5 is hydrogen, C.sub.1-4 alkyl or C.sub.3-7 cycloalkyl, or an isomer thereof or an acid addition salt thereof.