| abstract |
Provided are cyclic amidine compounds of Formula I or a pharmaceutically acceptable salt thereof:n n n [Formula I]n n n n n n n n [Meal:n n n A 1 and A 2 are a hydrogen atom, an optionally substituted alkyl group; Optionally substituted aryl group; Or an optionally substituted heterocyclic group;n n n X is -C (R 1 , R 2 ) -C (R 3 , R 4 )-, -C (R 5 ) = C (R 6 )-, -C (R 7 , R 8 ) -C (R 9 R 10 ) -C (R 11 , R 12 )-, or -C (R 13 , R 14 ) -C (R 15 , R 16 ) -NH-, wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 and R 16 are a hydrogen atom, a halogen atom, an optionally substituted alkyl group; Optionally substituted aryl group; or optionally substituted heterocyclic group).n n n The compound has a high affinity for the α4β2 nicotinic acetylcholine receptor, and by activating it exhibits a prophylactic or therapeutic effect on brain dysfunction. |