Pyrrolo[1,2-a]pyrazine derivatives as 5HT1A ligands

A method of treating a disorder or condition that can be treated by altering serotonin mediated neurotransmission in a mammal, comprising administering to such mammal an amount of a compound of formula I

• wherein R1 is phenyl, naphthyl, benzoxazolonyl, indolyl, indolonyl, benzimidazolyl, quinolyl, furyl, benzofuryl, thienyl, benzothienyl, oxazolyl, benzoxazolyl;
• R2 is H or (C1-C6)alkyl;
• R3 is phenyl, pyridinyl, pyrimidinyl, pyrazinyl, or pyridazinyl;
• R4 is H or (C1-C6)alkyl;
• R5 is H or (C1-C6)alkyl;
• wherein each group of R1 and R3 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, —SR4, —SOR4, —SO2R4, —NHSO2R4, —(C1-C6)alkoxy, —NR4R5, —NR4COR5, —CONR4R5, phenyl, —COR4, —COOR4, —(C1-C6)alkyl, —(C1-C6)alkyl substituted one to six halogens, —(C3-C6)cycloalkyl, and trifluoromethoxy;
• X is O, S, SO, SO2, NR4, C═O, CH(OH), CHR4,
• m is 0, 1 or 2;
• n is 0, 1 or 2;
• or
• a pharmaceutically acceptable salt thereof;
• that is effective in treating such disorder or condition.