Compounds as modulators of a mutant CFTR protein and its use for the treatment of diseases associated with malfunctioning of the CFTR protein

A compound of general formula (I): Formula ** ** tautomers, geometric isomers E and Z, optically active forms such as enantiomers, diastereomers and its racemate forms, or a mixture of stereoisomeric forms or pharmaceutically acceptable salts thereof or complexes thereof; wherein Z1 is independently selected from the group consisting of: -CnH (2n) -, which is branched or unbranched in which n is an integer of 1 to 5; -CnH (2n-2) - in E or Z geometric conformation which is branched or unbranched where n is an integer of 2 to 5; -CnH (2n-4) - which is branched or unbranched where n is an integer of 2 to 5; -CR'H-, -C2H3R'-, E or Z -C2HR'-, -C3H5R'-, E or Z -C3H3R '-, - OCH2-, -CH2O-, NR "CH2 -, - CH2NR' -; wherein R 'is independently selected from the group consisting of: -H, halogen, -NH2, -OH, -CN, CF3, -CHF2, -CH2F, -SH, - SCN, -CH3, -C2H5; wherein R "is independently selected from the group consisting of: -H, -CH3, -C2H5; where R1 and R2 are independently selected from the group consisting of aromatic ring or heteroaromatic ring, as a modulator of CFTR protein mutant for use in the treatment of cystic fibrosis.