Triazolopyridazine Derivatives for treating anxiety and enhancing cognition

A compound of formula I, or a pharmaceutically acceptable salt thereof:

• wherein
• Z represents C1-6alkyl, C3-7cycloalkyl, C4-7cycloalkenyl, phenyl, naphthyl, azetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, pyridinyl, quinolinyl, isoquinolinyl, pyridazinyl, pyrimidinyl, pyrazinyl, quinoxalinyl, furyl, benzofuryl, dibenzofuryl, thienyl, benzthienyl, pyrrolyl, indolyl, pyrazolyl, indazolyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, imidazolyl, benzimidazolyl, oxadiazolyl, thiadiazolyl, triazolyl, tetrazolyl, or di(C1-6)alkylamino, any of which groups may be optionally substituted with one or more of C1-6alkyl, phenyl(C1-6)alkyl, naphthyl(C1-6) alkyl, pyridyl(C1-6)alkyl, halogen, halo(C1-6)alkyl, cyano, cyano(C1-6)alkyl, hydroxy, hydroxymethyl, C1-6alkoxy, C3-7cycloalkyl(C1-6)alkoxy, C3-7cycloalkoxy, amino(C1-6) alkyl, di(C1-6)alkylamino(C1-6)alkyl, di(C1-6)alkylaminocarbonyl(C1-6)alkyl, N-(C1-6) alkylpiperidinyl, pyrrolidinyl(C1-6)alkyl, piperazinyl(C1-6)alkyl, morpholinyl(C1-6) alkyl, di(C1-6)alkylmorpholinyl(C1-6)alkyl or imidazolyl(C1-6)alkyl;
• R1 represents a five-membered heteroaromatic ring selected from oxazole, thiazole, isoxazole, isothiazole, imidazole, pyrazole, oxadiazole, thiadiazole, triazole and tetrazole, any of which five-membered heteroaromatic ring optionally substituted with one or more of C1-6alkyl, phenyl(C1-6)alkyl, naphthyl(C1-6)alkyl, pyridyl(C1-6)alkyl, halogen, halo(C1-6)alkyl, cyano, cyano(C1-6)alkyl, hydroxy, hydroxymethyl, C1-6alkoxy, C3-7cycloalkyl(C1-6)alkoxy, C3-7cycloalkoxy, amino(C1-6) alkyl, di(C1-6)alkylamino(C1-6)alkyl, di(C1-6)alkylaminocarbonyl(C1-6)alkyl, N-(C1-6) alkylpiperidinyl, pyrrolidinyl(C1-6)alkyl, piperazinyl(C1-6)alkyl, morpholinyl(C6-1) alkyl, di(C1-6)alkylmorpholinyl(C1-6)alkyl or imidazolyl(C1-6)alkyl;
• or
• R1 represents a six-membered heteroaromatic ring selected from pyrazine, pyrimidine and pyridazine, any of which six-membered heteroaromatic ring optionally substituted with one or more of C1-6alkyl, phenyl(C1-6)alkyl, naphthyl(C1-6) alkyl, pyridyl(C1-6)alkyl, halogen, halo(C1-6)alkyl, cyano, cyano(C1-6)alkyl, hydroxy, hydroxymethyl, C1-6alkoxy, C3-7cycloalkyl(C1-6)alkoxy, C37cycloalkoxy, amino(C1-6) alkyl, di(C1-6)alkylamino(C1-6)alkyl, di(C1-6)alkylaminocarbonyl(C1-6)alkyl, N-(C1-6) alkylpiperidinyl, pyrrolidinyl(C1-6)alkyl, piperazinyl(C1-6)alkyl, morpholinyl(C1-6) alkyl, di(C1-6)alkylmorpholinyl(C1-6)alkyl or imidazolyl(C1-6)alkyl;
• and
• R2 represents cyano(C1-6)alkyl, hydroxy(C1-6)alkyl, C3-7cycloalkyl(C1-6) alkyl, propargyl, azetidinyl carbonyl(C1-6)alkyl, pyrrolidinyl carbonyl(C1-6)alkyl, piperidinyl carbonyl(C1-6)alkyl, piperazinyl carbonyl(C1-6)alkyl, morpholinyl carbonyl(C1-6)alkyl, thiomorpholinyl carbonyl(C1-6)alkyl, phenyl(C1-6)alkyl, naphthyl(C1-6)alkyl, furylmethyl, indazolylmethyl, thienymethyl, thienylethyl, pyrazolylmethyl, oxazolylmethyl, oxazolylethyl, isoxazolylmethyl, thiazolylmethyl, thiazolylethyl, imidazolylmethyl, imidazolylethyl, benzimidazolylmethyl, oxadiazolylmethyl, oxadiazolylethyl, thiadiazolylmethyl, thiadiazolylethyl, triazolylmethyl, triazolylethyl, tetrazolylmethyl, tetrazolylethyl, pyridinylmethyl, pyridinylethyl, pyridazinylmethyl, pyrimidinylmethyl, pyrazinylmethyl, quinolinylmethyl, isoquinolinylmethyl or quinoxalinylmethyl, any of which groups may be optionally substituted with one or more of C1-6alkyl, phenyl(C1-6) alkyl, naphthyl(C1-6)alkyl, pyridyl(C1-6)alkyl, halogen, halo(C1-6)alkyl, cyano, cyano(C1-6)alkyl, hydroxy, hydroxymethyl, C1-6alkoxy, C3-7cycloalkyl(C1-6)alkoxy, C3-7cycloalkoxy, amino(C1-6)alkyl, di(C1-6)alkylamino(C1-6)alkyl, di(C1-6)alkylaminocarbonyl(C1-6)alkyl, N-(C1-6)alkylpiperidinyl, pyrrolidinyl(C1-6) alkyl, piperazinyl(C1-6)alkyl, morpholinyl(C1-6)alkyl, di(C1-6)alkylmorpholinyl(C1-6) alkyl or imidazolyl(C1-6)alkyl.