Pyrido (1.2-a) benzimidazole substituted in C-6 useful in the treatment of disorders of the central nervous system.

A compound of formula ** ** in which: R1 is independently selected from the group consisting of hydrogen; C1-C8; halogen, perfluoroalkyl C1- 4; hydroxy; C1-4 alkoxy; di (C1-4alkyl) amino; Not me; amino (C1-C8) amino; nitro; C1-C4 alkoxycarbonyl; and C1-C4 alkylthio; R2 is selected from the group consisting of hydrogen; C1-C6; aryl- (C1-C8); heteroaryl (C1-C4); (R4) 2N (CH2) p wherein R4 is the same or different and independently selected from H, C1-C4 alkyl, aralkyl, aryl or substituted aryl, independently selected substituents from C1-C4 alkyl, C1-C4, nitro , amino or halo; or R4 together with the nitrogen form a heterocyclic group selected from piperidinyl, pyrrolidinyl, morpholinyl, thiomorpholinyl, piperazinyl, imidazolyl, pyrazolyl, triazolyl, indolyl, indolinyl, benzimidazolyl, pyrrolyl or indazolyl; R5O (CH2) p R5S (CH2) p R5 is selected from alkyl of C1- C4, aralkyl, aryl or substituted aryl substituents independently selected from C1-C4 alkyl, C1-C4 alkyl, nitro, amino or halo and p is 1 -5; R3 is independently selected from the group consisting of aryl, substituted aryl, substituents are selected independently from C1-C8 alkyl; halo, C1-C4 perfluoroalkyl, hydroxy, C1-C4 alkyl, amino, nitro, di (C1-C4) amino, C1-C4 alkoxycarbonyl; alkylamino (C2-C6) alkyl, (C1-C8) alkylamino (C2-C6), di ((C1-C8) alkylamino (C2-C6), or C1-C4 alkylthio, a heteroaryl ring selected from pyridyl, thiazolyl , thiophenyl, furyl, indolyl, benzothiophenyl, pyridazinyl, pyrimidinyl, imidazolyl, indolinyl, quinolinyl, indazolyl, benzofuryl, triazinyl, pyrazinyl, isoquinolinyl, isoxazolyl, thiadiazolyl, benzothiazolyl, triazolyl, or benzotriazolyl, a heteroaryl ring substituted phenyl wherein the substituent is independently selected from oxo, halo, perfluoroalkyl of C1-C4 alkyl, nitro, amino, alkylthio C1-C4 alkyl, C1-C4 alkylamino C1-C4 alkylamino, di (C1-C4) amino, carboxy or (C1-C4 ) carbonyl; and cycloalkyl having 3-8 carbon atoms; and pharmaceutically acceptable salts thereof.