Derivatives 2,3,4,9-tetrahydro-1H-carbazole as CRTH2 receptor antagonists.

A compound selected from the group consisting of 2,3,4,9-tetrahydro-1H-carbazoles of formula I: R 3 R 2 R 4 in which R 1 CO INOR 5 R 6 R 2H 1, R 2, R 3 and R 4 independently represent hydrogen, alkyl, alkoxy, halogen, nitro, cyano, trifluoromethyl, or formyl; R 5 represents hydrogen, alkyl, or -CF3; R 6 represents alkoxy, aryl, or -NR 7 R 8; R 7 and R 8 independently represent hydrogen, alkyl, cyano-alkyl, alkenyl, aryl, arylalkyl, phenylcarbonyl, cycloalkyl, pyridyl-alkyl, thienyl-alkyl, furanyl-alkyl, or imidazolyl-alkyl; or R 7 and R 8 together with the nitrogen atom to which they are attached, form a heterocyclic ring system of 5, 6, 7 or 8 membered ring with one to three heteroatoms which are selected from nitrogen, oxygen and sulfur and said ring system It is optionally substituted with (i) one or two benzene rings linked, which benzene rings are unsubstituted or substituted with one or two substituents independently selected from C1-C4 alkyl, C1-C4 alkoxy, halogen, -CF3, -OCF3 and; (Ii) a phenyl ring unsubstituted; (Iii) a phenyl ring mono- or di-substituted, wherein the substituents are independently selected from halogen, C1-C4alkyl, C1-C4alkoxy, -CF3, and - OCF3; or (iv) phenylalkyl wherein the alkyl portion is substituted with phenyl; or an optically pure enantiomer, a mixture of enantiomers such as a racemate, an optically pure diastereomer, a mixture of diastereomers, mixtures of one enantiomers and diastereomers, diastereomeric racemate such as a meso-form or a geometric isomer; or a solvate or morphological form; or a pharmaceutically acceptable salt thereof; wherein the terms "alkyl" and "cycloalkyl", if not explicitly indicated to the contrary, have the following meanings: The term "alkyl", as used herein, alone or in any combination, it refers to a saturated aliphatic group including a straight or branched hydrocarbon chain containing 1 to 7 carbon atoms, wherein the alkyl group may be optionally substituted with one or more substituents each independently selected from alkenyl, alkoxy, alkoxycarbonyl, alkylcarbonyl, alkylcarbonyloxy, alkylendioxy, alkylsulfinyl, alkylsulfonyl, alkylthio, alkynyl, amino, aminocarbonyl, aryl, arylalkenyl, arylalkyloxy, aryloxy, aryloxycarbonyl, arylsulfinyl, arylsulfonyl, arylthio, carboxy, cyano, formyl, halogen, haloalkoxy, heterocyclyl, hydroxy, mercapto, and nitro, linked to any carbon atom of the alkyl moiety. The term "cycloalkyl", as used herein, alone or in any combination, refers to a portion of saturated cyclic hydrocarbon containing from 3 to 10 carbon atoms ,, wherein in polycyclic cycloalkyl groups one of the distal rings may be aromatic; wherein said cycloalkyl group is optionally substituted with one or more groups, each individually and independently selected from alkenyl, alkoxy, alkoxyalkyl, alkoxycarbonyl, alkoxycarbonylalkyl, alkyl, alkylcarbonyl, alkylcarbonylalkyl, alkylcarbonyloxy, alkylendioxy, alkylsulfinyl, alkylsulfinylalkyl, alkylsulfonyl, alkylsulfonylalkyl, alkylthio, alkylthioalkyl, alkynyl, amino, aminoalkyl, aminocarbonyl, aminocarbonyl, aryl, arylalkenyl, arylalkyloxy, arylalkyl, aryloxy, aryloxycarbonyl, aryloxycarbonylalkyl, arylsulfinyl, arylsulfinylalkyl, arylsulfonyl, arylsulfonylalkyl, arylthio, arylthioalkyl, carboxy, carboxyalkyl, cyano, cyanoalkyl, formyl, formylalkyl, halogen, haloalkoxy, haloalkyl, heterocyclyl, hydroxy, hydroxyalkyl, mercapto and nitro.