A compound having the structure for use in a method of treatment which comprises improvement of a condition involving phosphodiesterase type 9 wherein R2 is cyclized with R3, wherein R1, R2 and R3 are: R1 is selected from the group consisting of H and wherein R6 is selected from the group consisting of H, -CH 3, -C 2 H 5, and -C 3 H 7 R2 is selected from the group consisting of wherein R7 is selected from the group consisting of H, -CH 3, -C 2 H 5, and -C 3 H 7 wherein * denotes the cyclization point, and R3 is wherein * denotes the cyclization point, and wherein R8 is selected from the group consisting of H, C 1 -C 6 alkyl, branched C 3 -C 6 alkyl, C 3 -C 6 cycloalkyl, C 6 -C 10 aryl, substituted C 6 -C 10 aryl, C 3 -C 9 heteroaryl, substituted C 3 -C 9 heteroaryl, C 1 -C 6 alkoxy, branched C 3 -C 6 alkoxy, C 3 -C 6 cycloalkoxy, C 6 -C 10 aryloxy, substituted C 6 -C 10 aryloxy, C 3 -C 9 heteroaryloxy, substituted C 3 -C 9 heteroaryloxy; and R4 is selected from the group consisting of C 6 -C 10 aryl, substituted C 6 -C 10 aryl, C 3 -C 9 heteroaryl, substituted C 3 -C 9 heteroaryl, C 3 -C 6 heterocyclyl, substituted C 3 -C 6 heterocyclyl, C 3 -C 6 cycloalkyl, and substituted C 3 -C 6 cycloalkyl; R5 is selected from the group consisting of hydrogen, F, Cl, CN, -CH 3, -C 2 H 5, -C 3 H 7, and -CF 3; A is absent or -CH 2 - and tautomers and pharmaceutically acceptable acid addition salts thereof, and polymorphic forms thereof. wherein R2 is cyclized with R3, wherein R1, R2 and R3 are: R1 is selected from the group consisting of H and wherein R6 is selected from the group consisting of H, -CH 3, -C 2 H 5, and -C 3 H 7 R2 is selected from the group consisting of wherein R7 is selected from the group consisting of H, -CH 3, -C 2 H 5, and -C 3 H 7 wherein * denotes the cyclization point, and R3 is wherein * denotes the cyclization point, and wherein R8 is selected from the group consisting of H, C 1 -C 6 alkyl, branched C 3 -C 6 alkyl, C 3 -C 6 cycloalkyl, C 6 -C 10 aryl, substituted C 6 -C 10 aryl, C 3 -C 9 heteroaryl, substituted C 3 -C 9 heteroaryl, C 1 -C 6 alkoxy, branched C 3 -C 6 alkoxy, C 3 -C 6 cycloalkoxy, C 6 -C 10 aryloxy, substituted C 6 -C 10 aryloxy, C 3 -C 9 heteroaryloxy, substituted C 3 -C 9 heteroaryloxy; and R4 is selected from the group consisting of C 6 -C 10 aryl, substituted C 6 -C 10 aryl, C 3 -C 9 heteroaryl, substituted C 3 -C 9 heteroaryl, C 3 -C 6 heterocyclyl, substituted C 3 -C 6 heterocyclyl, C 3 -C 6 cycloalkyl, and substituted C 3 -C 6 cycloalkyl; R5 is selected from the group consisting of hydrogen, F, Cl, CN, -CH 3, -C 2 H 5, -C 3 H 7, and -CF 3; A is absent or -CH 2 - and tautomers and pharmaceutically acceptable acid addition salts thereof, and polymorphic forms thereof. R1 is selected from the group consisting of H and wherein R6 is selected from the group consisting of H, -CH 3, -C 2 H 5, and -C 3 H 7 R2 is selected from the group consisting of wherein R7 is selected from the group consisting of H, -CH 3, -C 2 H 5, and -C 3 H 7 wherein * denotes the cyclization point, and R3 is wherein * denotes the cyclization point, and wherein R8 is selected from the group consisting of H, C 1 -C 6 alkyl, branched C 3 -C 6 alkyl, C 3 -C 6 cycloalkyl, C 6 -C 10 aryl, substituted C 6 -C 10 aryl, C 3 -C 9 heteroaryl, substituted C 3 -C 9 heteroaryl, C 1 -C 6 alkoxy, branched C 3 -C 6 alkoxy, C 3 -C 6 cycloalkoxy, C 6 -C 10 aryloxy, substituted C 6 -C 10 aryloxy, C 3 -C 9 heteroaryloxy, substituted C 3 -C 9 heteroaryloxy; and R4 is selected from the group consisting of C 6 -C 10 aryl, substituted C 6 -C 10 aryl, C 3 -C 9 heteroaryl, substituted C 3 -C 9 heteroaryl, C 3 -C 6 heterocyclyl, substituted C 3 -C 6 heterocyclyl, C 3 -C 6 cycloalkyl, and substituted C 3 -C 6 cycloalkyl; R5 is selected from the group consisting of hydrogen, F, Cl, CN, -CH 3, -C 2 H 5, -C 3 H 7, and -CF 3; A is absent or -CH 2 - and tautomers and pharmaceutically acceptable acid addition salts thereof, and polymorphic forms thereof.