Novel aromatic heterocyclic carboxylic acid amide derivatives useful as potassium channel modulators

An aromatic heterocyclic carboxylic acid amide derivative of Formula I

• a stereoisomer or a mixture of its stereoisomers, or a pharmaceutically-acceptable addition salt thereof, wherein
• X represents alkyl, cycloalkyl, alkenyl, alkynyl, methoxyiminomethyl, amino, N-alkyl-amino, N,N-dialkyl-amino, N-aryl-amino, N,N-diaryl-amino, alkyl-sulfonyl-amino, aryl-sulfonyl-amino, alkyl-carbonyl-amino, aryl-carbonyl-amino, phenyl or a five- or six-membered heterocyclic group selected from imidazolyl, 2-oxopyrrolidin-1-yl, piperidinyl, morpholin-4-yl and pyridinyl, which phenyl and heterocyclic group are optionally substituted one or more times with substituents selected from the group consisting of alkyl, halo, trifluoromethyl, cyano, hydroxy, phenyl and alkoxy-carbonyl;
• L is absent (i.e. representing a covalent bond), or represents the linking group —CH2— or —CONH—;
• HET represents a five-membered aromatic heterocyclic group selected from furanyl, thienyl, oxazolyl, thiazolyl, pyrazolyl and triazolyl, which heterocyclic group is optionally substituted one or more times with substituents selected from the group consisting of alkyl, halo, trifluoromethyl and cyano;
• R1 represents tetrazolyl, tetrazolyl-alkoxy, N-phenyl-carbamoyl, alkyl-sulfonyl-amino-carbonyl, N-alkyl-sulfonyl-carboxamide, N-phenyl-sulfonyl-carboxamide, carboxy, N-cyano-carboxamide, sulfamoyl, sulfonic acid, sulfonic acid alkyl ester, sulfonic acid phenyl ester, or a oxadiazolyl oxo- or thio-derivative selected from 5-oxo-4,5-dihydro-[1,2,4]oxadiazol-3-yl and 5-thioxo-4,5-dihydro-[1,2,4]oxadiazol-3-yl;
• R2 represents halo or trifluoromethyl;
• and
• R3 represents hydrogen, halo, trifluoromethyl, amino, N-alkyl-amino, N,N-dialkyl-amino, piperidinyl or morpholinyl.