2,7-substituted octahydro-1H-pyrido›1,2-a!pyrazine derivatives

A compound of the formula ##STR88## wherein Ar is phenyl, naphthyl, benzoxazolonyl, indolyl, indolonyl, benzimidazolyl, quinolyl, furyl, benzofuryl, thienyl, benzothienyl, oxazolyl, benzoxazolyl;

• Ar.sup.1 is phenyl, pyridinyl, pyridazinyl, pyrimidinyl, or pyrazinyl;
• A is O, S, SO, SO.sub.2, C.dbd.O, CHOH, or -(CR.sup.3 R.sup.4)-;
• n is 0, 1 or 2;
• each of Ar and Ar.sup.1 may be independently and optionally substituted with one to four substituents independently selected from the groups consisting of fluoro, chloro, bromo, iodo, cyano, nitro, thiocyano, --SR, --SOR, --SO.sub.2 R, --NHSO.sub.2 R, -(C.sub.1 -C.sub.6)alkoxy, --NR.sup.1 R.sup.2, --NRCOR.sup.1, --CONR.sup.1 R.sup.2, Ph, --COR, COOR, -(C.sub.1 -C.sub.6)alkyl, -(C.sub.1 -C.sub.6)alkyl substituted with one to six halogens, -(C.sub.3 -C.sub.6)cycloalkyl, and trifluoromethoxy;
• each and every R, R.sup.1, and R.sup.2 is independently selected from the group consisting of hydrogen, -(C.sub.1 -C.sub.6)alkyl, -(C.sub.1 -C.sub.6)alkyl substituted with one to thirteen halogens selected from fluorine, chlorine, bromine and iodine, phenyl, benzyl, -(C.sub.2 -C.sub.6)alkenyl, -(C.sub.3 -C.sub.6)cycloalkyl, and -(C.sub.1 -C.sub.6)alkoxy;
• each and every R.sup.3 and R.sup.4 is independently selected from a group consisting of hydrogen, methyl, ethyl, n-propyl, and i-propyl;
• diastereomeric and optical isomers thereof;
• and
• pharmaceutically acceptable salts thereof.