A compound of the general formula wherein: n = 2; R1 is selected from alkyl, alkenyl, alkynyl, which can be optionally substituted by one or more substituents selected from Y; R2 is hydrogen; R3 is selected from hydrogen, halogen, aryl; wherein aryl can be optionally substituted by one or more substituents selected from Y; R4 is selected from: - arylalkyl, aryloxyalkyl; which can be optionally substituted by one or more substituents selected from Y; - wherein: m = 1-6; R7 and R8 together constitute a heterocycle; the heterocycle can include one or more heteroatom from N, O and S; Y is selected from: hydroxy, thio, halogen, cyano, trifluoromethoxy, trifluoromethyl, carboxy, carboxy methyl, carboxyethyl, alkyl, alkoxy, alkylamino, aryl, aryl sulfonylalkyl, aryloxy, arylalkoxy, amino, NR5R6, azido, nitro, guanidino, amidino, phosphono, oxo, carbamoyl, alkylsulfonyl, alkylsulfinyl, alkylthio, two Y groups can form a methylenedioxy; wherein R5 and R6 are independently selected from: hydrogen, alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl; wherein alkyl, aryl and heteroaryl groups can be optionally substituted by one or more substituents selected from Y; R5 and R6 together can constitute a heterocycle; the heterocycle can include one or more heteroatom from N, O and S; as well as its racemic forms, tautomers, enantiomers, diastereomers, epimers and polymorphs, and mixtures thereof, and the pharmaceutically acceptable salts thereof. n = 2; R1 is selected from alkyl, alkenyl, alkynyl, which can be optionally substituted by one or more substituents selected from Y; R2 is hydrogen; R3 is selected from hydrogen, halogen, aryl; wherein aryl can be optionally substituted by one or more substituents selected from Y; R4 is selected from: - arylalkyl, aryloxyalkyl; which can be optionally substituted by one or more substituents selected from Y; - wherein: m = 1-6; R7 and R8 together constitute a heterocycle; the heterocycle can include one or more heteroatom from N, O and S; - arylalkyl, aryloxyalkyl; which can be optionally substituted by one or more substituents selected from Y; - wherein: m = 1-6; R7 and R8 together constitute a heterocycle; the heterocycle can include one or more heteroatom from N, O and S; m = 1-6; R7 and R8 together constitute a heterocycle; the heterocycle can include one or more heteroatom from N, O and S; Y is selected from: hydroxy, thio, halogen, cyano, trifluoromethoxy, trifluoromethyl, carboxy, carboxy methyl, carboxyethyl, alkyl, alkoxy, alkylamino, aryl, aryl sulfonylalkyl, aryloxy, arylalkoxy, amino, NR5R6, azido, nitro, guanidino, amidino, phosphono, oxo, carbamoyl, alkylsulfonyl, alkylsulfinyl, alkylthio, two Y groups can form a methylenedioxy; wherein R5 and R6 are independently selected from: hydrogen, alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl; wherein alkyl, aryl and heteroaryl groups can be optionally substituted by one or more substituents selected from Y; R5 and R6 together can constitute a heterocycle; the heterocycle can include one or more heteroatom from N, O and S; as well as its racemic forms, tautomers, enantiomers, diastereomers, epimers and polymorphs, and mixtures thereof, and the pharmaceutically acceptable salts thereof. hydroxy, thio, halogen, cyano, trifluoromethoxy, trifluoromethyl, carboxy, carboxy methyl, carboxyethyl, alkyl, alkoxy, alkylamino, aryl, aryl sulfonylalkyl, aryloxy, arylalkoxy, amino, NR5R6, azido, nitro, guanidino, amidino, phosphono, oxo, carbamoyl, alkylsulfonyl, alkylsulfinyl, alkylthio, two Y groups can form a methylenedioxy; wherein R5 and R6 are independently selected from: hydrogen, alkyl, aryl, arylalkyl, heteroaryl, heteroarylalkyl; wherein alkyl, aryl and heteroaryl groups can be optionally substituted by one or more substituents selected from Y; R5 and R6 together can constitute a heterocycle; the heterocycle can include one or more heteroatom from N, O and S;