6-cyclylmethyl- and 6-alkylmethyl pyrazolo[3,4-D]pyrimidines, methods for their preparation and methods for their use to treat impairments of perception, concentration learning and/or memory

A compound of the formula

• in which
• R1 is C1-C8-alkyl, C2-C6-alkenyl, C2-C6-alkynyl or C3-C8-cycloalkyl, where C1-C8-alkyl is optionally substituted by oxo, and
• where C1-C8-alkyl, C2-C6-alkenyl, C2-C6-alkynyl and C3-C8-cycloalkyl are optionally substituted by up to 3 radicals independently of one another selected from the group of C1-C6-alkyl, C1-C6-alkoxy, hydroxycarbonyl, cyano, amino, nitro, hydroxy, C1-C6-alkylamino, halogen, trifluoromethyl, trifluoromethoxy, C6-C10-arylcarbonylamino, C1-C6-alkylcarbonylamino, C1-C6-alkylaminocarbonyl, C1-C6-alkoxycarbonyl, C6-C10-arylaminocarbonyl, heteroarylaminocarbonyl, heteroarylcarbonylamino, C1-C6-alkylsulphonylamino, C1-C6-alkylsulphonyl, C1-C6-alkylthio,
• where
• C1-C6-alkyl, C1-C6-alkoxy, C1-C6-alkylamino, C6-C10-arylcarbonylamino, C1-C6-alkylcarbonylamino, C1-C6-alkylaminocarbonyl, C1-C6-alkoxycarbonyl, C6-C10-arylaminocarbonyl, heteroarylaminocarbonyl, heteroarylcarbonylamino, C1-C6-alkylsulphonylamino, C1-C6-alkylsulphonyl and C1-C6-alkylthio are optionally substituted by one to three radicals independently of one another selected from the group of hydroxy, cyano, halogen, trifluoromethyl, trifluoromethoxy, hydroxycarbonyl and a group of the formula —NR3R4,
• where
• R3 and R4 are independently of one another hydrogen or C1-C6-alkyl,
• or
• R3 and R4 together with the nitrogen atom to which they are bonded are 5- to 8-membered heterocyclyl,
• R2 is phenyl or heteroaryl, where phenyl is substituted by 1 to 3 radicals and heteroaryl is optionally substituted by 1 to 3 radicals in each case independently of one another selected from the group of C1-C6-alkyl, C1-C6-alkoxy, hydroxycarbonyl, cyano, trifluoromethyl, trifluoromethoxy, amino, nitro, hydroxy, C1-C6-alkylamino, halogen, C6-C10-arylcarbonylamino, C1-C6-alkylcarbonylamino, C1-C6-alkylaminocarbonyl, C1-C6-alkoxycarbonyl, C6-C10-arylaminocarbonyl, heteroarylaminocarbonyl, heteroarylcarbonylamino, C1-C6-alkylsulphonylamino, C1-C6-alkylsulphonyl and C1-C6-alkylthio,
• where C1-C6-alkyl, C1-C6-alkoxy, C1-C6-alkylamino, C6-C10-arylcarbonylamino, C1-C6-alkylcarbonylamino, C1-C6-alkylaminocarbonyl, C1-C6-alkoxycarbonyl, C6-C10-arylaminocarbonyl, heteroarylaminocarbonyl, heteroarylcarbonylamino, C1-C6-alkylsulphonylamino, C1-C6-alkylsulphonyl and C1-C6-alkylthio are optionally substituted by one to three radicals independently of one another selected from the group of hydroxy, cyano, halogen, trifluoromethyl, trifluoromethoxy, hydroxycarbonyl and a group of the formula —NR3R4,
• where
• R3 and R4 have the meanings indicated above,
• or a salt thereof.