A compound of the formula: wherein X is S or NR b; Y is CR 3; ring A is aryl or heteroaryl; at each occurrence, R, which may be the same or different, is selected from hydrogen, nitro, cyano, halogen, -OR a, alkyl, alkenyl, haloalkyl, cyanoalkyl or cyanoalkyloxy; R 1 and R 3, which may be the same or different, are each independently selected from hydrogen, halogen, nitro, cyano, -COOH, alkyl, alkenyl, alkynyl, or haloalkyl; or R 1 and R 3 together with the carbon atoms to which they were attached may form a 5 to 7 membered cyclic ring, which may be substituted or unsubstituted, saturated, unsaturated or partially saturated, which cyclic ring may optionally contain one or more heteroatoms selected from O, NR b or S; R 2 is aryl or heteroaryl, each of which may be optionally mono- or polysubstituted with substituent(s) independently selected from the group consisting of halogen, hydroxyl, nitro, cyano, -COOH, -NR 4 R 5, acyl, alkyl, alkenyl, alkoxy, cyanoalkoxy, haloalkyl, haloalkyloxy, cycloalkyl, cycloalkylalkyl and cycloalkylalkoxy; at each occurrence, R a, which may be the same or different, is selected from the group consisting of hydrogen, alkyl, haloalkyl, cyanoalkyl, alkenyl, cycloalkyl, alkoxyalkyl, cycloalkylalkyl, substituted or unsubstituted arylalkyl, heteroarylalkyl and heterocyclylalkyl; at each occurrence, R b is selected from hydrogen, alkyl or arylalkyl; at each occurrence, R 4 and R 5, which may be the same or different, are independently selected from hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkylalkyl, cycloalkenyl, arylalkyl, heteroarylalkyl or heterocyclylalkyl; and 'n' is an integer ranging from 0 to 5, inclusive; or a pharmaceutically acceptable salt thereof. wherein X is S or NR b; Y is CR 3; ring A is aryl or heteroaryl; at each occurrence, R, which may be the same or different, is selected from hydrogen, nitro, cyano, halogen, -OR a, alkyl, alkenyl, haloalkyl, cyanoalkyl or cyanoalkyloxy; R 1 and R 3, which may be the same or different, are each independently selected from hydrogen, halogen, nitro, cyano, -COOH, alkyl, alkenyl, alkynyl, or haloalkyl; or R 1 and R 3 together with the carbon atoms to which they were attached may form a 5 to 7 membered cyclic ring, which may be substituted or unsubstituted, saturated, unsaturated or partially saturated, which cyclic ring may optionally contain one or more heteroatoms selected from O, NR b or S; R 2 is aryl or heteroaryl, each of which may be optionally mono- or polysubstituted with substituent(s) independently selected from the group consisting of halogen, hydroxyl, nitro, cyano, -COOH, -NR 4 R 5, acyl, alkyl, alkenyl, alkoxy, cyanoalkoxy, haloalkyl, haloalkyloxy, cycloalkyl, cycloalkylalkyl and cycloalkylalkoxy; at each occurrence, R a, which may be the same or different, is selected from the group consisting of hydrogen, alkyl, haloalkyl, cyanoalkyl, alkenyl, cycloalkyl, alkoxyalkyl, cycloalkylalkyl, substituted or unsubstituted arylalkyl, heteroarylalkyl and heterocyclylalkyl; at each occurrence, R b is selected from hydrogen, alkyl or arylalkyl; at each occurrence, R 4 and R 5, which may be the same or different, are independently selected from hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkylalkyl, cycloalkenyl, arylalkyl, heteroarylalkyl or heterocyclylalkyl; and 'n' is an integer ranging from 0 to 5, inclusive;