Abstract: A class of [1,8] naphthyridine analogues which are substituted in the 4-position by a substituted phenyl ring. These compounds are ligands for GABAA receptors and useful in the therapy of deleterious mental states such as anxiety.

Abstract: A class of 3-phenylimidazo[1,2-c]pyrimidine derivatives, substituted at the meta position of the phenyl ring by an optionally substituted aryl or heteroaryl group which is directly attached or bridged by an oxygen atom or a —NH— linkage, are selective ligands for GABAA receptors, in particular having good affinity for the &agr;2 and/or &agr;3 subunit thereof, and are accordingly of benefit in the treatment and/or prevention of adverse conditions of the central nervous system, including anxiety and convulsions.

Abstract: A class of imidazo[1,2-&agr;]pyrimidine derivatives, substituted at the 3-position by an optionally substituted five-membered or six-membered heteroaromatic ring, are selective ligands for GABAA receptors, in particular having good affinity for the &agr;2 and/or &agr;3 and/or &agr;5 subunit thereof, and are accordingly of benefit in the treatment and/or prevention of adverse conditions of the central nervous system, including anxiety, convulsions and cognitive disorders.

Abstract: A class of substituted or 6,7-ring fused [1, 2, 3]triazolo[1,5-&agr;]-pyrimidine derivatives, possessing an optionally substituted cycloalkyl, phenyl or heteroaryl substituent at the 3-position and an amino moiety at the 5-position, are selective ligands for GABAA receptors, in particular having high affinity for the &agr;2 and/or &agr;3 subunit thereof, and are accordingly of benefit in the treatment and/or prevention of disorders of the central nervous system, including anxiety and convulsions.

Abstract: A class of pyrazino[2,3-d]pyridazine derivatives, possessing an optionally substituted cycloalkyl, phenyl or heteroaryl substituent at the 5-position, a substituted alkoxy moiety at the 3-position, and a range of substituents at the 2-position, are selective ligands for GABAA receptors, in particular having high affinity for the &agr;2 and/or &agr;3 and/or &agr;5 subunit thereof, and are accordingly of benefit in the treatment and/or prevention of adverse conditions of the central nervous system, including anxiety, convulsions and cognitive disorders.

Abstract: A class of substituted 1,2,4-triazolo[4,3b]pyridazine derivatives, possessing a fluoro-substituted phenyl ring at the 3-position and a heteroaryl-methoxy moiety at the 6-position, are selective ligands for GABAA receptors, in particular having high affinity for the &agr;2 and/or &agr;3 subunit thereof, and are accordingly of benefit in the treatment and/or prevention of disorders of the central nervous system, including anxiety and convulsions.

Abstract: 1,2,4-triazolo[4,3-b]pyridazine derivatives, possessing an optionally substituted cycloalkyl, phenyl or heteroaryl substituent at the 3-position, a substituted alkoxy moiety at the 6-position, an optionally substituted N-linked nitrogen-containing aliphatic ring at the 7-position, and a chloro at the 8-position are selective ligands for GABAZA receptors, in particular having high affinity for the &agr;2 and/or &agr;3 subunit thereof, are useful in the treatment of anxiety and convulsions.

Abstract: A class of 7-phenylimidazo[1,2-b][1,2,4]triazine derivatives, substituted at the meta position of the phenyl ring by a (cyano)(fluoro)phenyl moiety, being selective ligands for GABAA receptors, in particular having good affinity for thee &agr;2 and/or &agr;3 subunit thereof, are accordingly of benefit in the treatment and/or prevention of adverse conditions of the central nervous system, including anxiety and convulsions.

Abstract: A class of 7-phenylimidazo[1,2-b][1,2,4]triazine derivatives, substituted at the meta position of the phenyl ring by an optionally substituted aryl or heteroaryl group which is directly attached or bridged by an oxygen atom or a —NH— linkage, being selective ligands for GABAA receptors, in particular having good affinity for the &agr;2 and/or &agr;3 and/or &agr;5 subunit thereof, are accordingly of benefit in the treatment and/or prevention of adverse conditions of the central nervous system, including anxiety, convulsions and cognitive disorders.

Abstract: A class of imidazo[1,2-&agr;]pyrazine analogues substituted in the 3-position by a substituted phenyl ring, being selective ligands for GABAA receptors which interact more favourably with the &agr;2 and/or &agr;3 subunit than with the &agr;1 subunit, are accordingly of benefit in the treatment and/or prevention of a variety of disorders of the central nervous system, including anxiety and convulsions, with a reduced propensity to cause sedation.

Abstract: A class of 7-phenylimidazo[1,2-b][1,2,4]triazine derivatives, substituted at the meta position of the phenyl ring by a (cyano)(fluoro)phenyl moiety, being selective ligands for GABAA receptors, in particular having good affinity for thee &agr;2 and/or &agr;3 subunit thereof, are accordingly of benefit in the treatment and/or prevention of adverse conditions of the central nervous system, including anxiety and convulsions.

Abstract: A class of 3-phenylimidazo(1,2-a)pyrimidine derivatives (of Formula I, or salt or prodrug thereof: I) wherein Y represents a chemical bond, an oxygen atom, or a —NH— linkage; Z represents an optionally substituted aryl or heteroaryl group; R1 represents hydrogen, hydrocarbon, a heterocyclic group, halogen, cyano trifluoromethyl, nitro, —ORa, —SRa, —SORa, —SO2Ra, —SO2NRaRb, —NRaRb, —NRaCORb, —NRaCO2Rb, —CORa, CO2Ra, —CONRaRb or —CRa═NORb; and Ra and Rb independently represent hydrogen, hydrocarbon or a heterocyclic group.

Abstract: 7-(1,1 -Dimethylethyl)-6-(2-ethyl-2H-1,2,4-triazol-3-ylmethoxy)-3-(2-fluorophenyl)-1,2,4-triazolo[4,3-b]pyridazine, and pharmaceutically acceptable salts thereof are selective ligands for GABAA receptors useful in the treatment of disorders of the central nervous system.

Abstract: A class of 3-phenylimidazo(1,2-&agr;) pyrimidine derivatives (of Formula I, or salt or prodrug thereof: I) wherein Y represents a chemical bond, an oxygen atom, or a —NH— linkage; Z represents an optionally substituted aryl or heteroaryl group; R1 represents hydrogen, hydrocarbon, a heterocyclic group, halogen, cyano trifluoromethyl, nitro, —ORa, —SRa, —SORa, —SO2Ra, —SO2NRaRb, —NRaRb, —NRaCORb, —NRaCO2Rb, —CORa, CO2Ra, —CONRaRb or —CRa═NORb; and Ra and Rb independently represent hydrogen, hydrocarbon or a heterocyclic group.

Abstract: A class of 7-phenylimidazo[1,2-b][1,2,4]triazine derivatives, substituted at the meta position of the phenyl ring by a (cyano)(fluoro)phenyl moiety, being selective ligands for GABAA receptors, in particular having good affinity for the &agr;2 and/or &agr;3 subunit thereof, are accordingly of benefit in the treatment and/or prevention of adverse conditions of the central nervous system, including anxiety and convulsions.

Abstract: A class of substituted 1,2,4-triazolo[4,3-b]pyridazine derivatives, possessing a difluoro- or trifluoro-substituted phenyl ring at the 3-position, a triazolyl-methoxy moiety at the 6-position, and a tert-butyl group at the 7-position, are selective ligands for GABAA receptors, in particular having high affinity for &agr;2 and/or &agr;3 subunit thereof, and are accordingly of benefit in the treatment and/or prevention of disorders of the central nervous system, including anxiety and convulsions.

Abstract: A class of substituted 1,2,4-triazolo[4,3-]pyridazine derivatives, possessing an optionally substituted cycloalkyl, phenyl or heteroaryl substituent at the 3-position, a substituted alkoxy moiety at the 6-position, and an optionally substituted bicycloalkyl ring system at the 7-position, are selective ligands for GABAA receptors, in particular having high affinity for the &agr;2 and/or &agr;3 subunit thereof, and are accordingly of benefit in the treatment and/or prevention of disorders of the central nervous system, including anxiety and convulsions.

Abstract: A class of pyrido[2,3-d]pyridazine derivatives, possessing an optionally substituted cycloalkyl, phenyl or heteroaryl substituent at the 8-position, a substituted alkoxy moiety at the 2-position, and a range of substituents at the 3-position, are selective ligands for GABAA receptors, in particular having high affinity for the &agr;2 and/or &agr;3 and/or &agr;5 subunit thereof, and are accordingly of benefit in the treatment and/or prevention of adverse conditions of the central nervous system, including anxiety, convulsions and cognitive disorders.

Abstract: 1,2,4-triazolo[4,3-b]pyridazine derivatives, possessing a fluoro-substituted phenyl ring at the 3-position and a heteroaryl-alkoxy moiety at the 6-position, are selective ligands for GABAA receptors, in particular having high affinity for the &agr;2 and/or &agr;3 subunit thereof, are useful in the treatment of anxiety and convulsions.

Abstract: A class of substituted or 6,7-ring fused 1,2,3-triazolo[4,5-b]pyridine derivatives, possessing an optionally substituted cycloalkyl, phenyl or heteroaryl substituent at the 3-position and a substituted alkoxy moiety at the 5-position, are selective ligands for GABAA receptors, in particular having high affinity for the &agr;2 and/or &agr;3 subunit thereof, and are accordingly of benefit in the treatment and/or prevention of disorders of the central nervous system, including anxiety and convulsions.