5- or 6-substituted .beta.-carboline-3-carboxylic acid esters of Formula I ##STR1## wherein R.sup.1 is hydrogen, nitrilo, halogen, lower alkyl or lower alkoxy, and R.sup.3 is a branched C.sub.3-6 alkyl group which is optionally substituted by halogen, or a C.sub.3-6 cycloalkyl group which is optionally methyl-substituted, are valuable pharmaceuticals.
                            式I中的5-或6-取代的β-咔啉-3-
羧酸酯化合物,其中R1为氢、
氨基、卤素、较低的烷基或较低的烷氧基,而R3为分支的C3-6烷基,可选地取代卤素,或C3-6环烷基,可选地甲基取代,是有价值的药物。