Dihydrobenzofuran and dihydrobenzothiophene 2,4-pentadienoic acid derivatives having selective activity for retinoid X (RXR) receptors

A compound of the formula

• where X is O or S;
• Y is a bivalent cycloalkyl or cycloalkenyl radical optionally substituted with one to four R4 groups, the cycloalkenyl radical having 5 or 6 carbons and one double bond, or Y is a bivalent aryl or 5 or 6 membered heteroaryl radical having 1 to 3 heteroatoms selected from N, S and O, said aryl or heteroaryl groups optionally substituted with 1 to 4 R4 groups with the proviso that the cycloalkyl or the cycloalkenyl radical is not substituted on the same carbon with the condensed cyclic moiety and with the diene containing moiety;
• R1 is independently H, alkyl of 1 to 6 carbons, or fluoroalkyl of 1 to 6 carbons;
• R2 is independently H, alkyl of 1 to 8 carbons, or fluoroalkyl of 1 to 8 carbons;
• R′2 is independently H, alkyl of 1 to 8 carbons, or fluoroalkyl of 1 to 8 carbons;
• R3 is hydrogen, alkyl of 1 to 10 carbons, fluoro substituted alkyl of 1 to 10 carbons, halogen, alkoxy of 1 to 10 carbons, or alkylthio of 1 to 10 carbons;
• NO2, NH2, NHCO(C1-C6 alkyl, NHCO(C1-C6)alkenyl, NR1H or N(R1)2, benzyloxy, C1-C6alkyl-substituted benzyloxy, or R3 is selected from the groups shown below,
• R4 is H, halogen, alkyl of 1 to 10 carbons, fluoro substituted alkyl of 1 to 6 carbons, alkoxy of 1 to 10 carbons, or alkylthio of 1 to 10 carbons;
• m is an integer having the values of 0 to 3;
• r is an integer having the values of 1 to 10;
• s is an integer having the values 1 to 4;
• t is an integer having the values 1 to 5;
• represents a 5 or 6 membered heteroaryl ring having 1 to 3 heteroatoms selected from the group consisting of N, S and O;
• B is COOH or a pharmaceutically acceptable salt thereof, COOR8, COOCH2COR7, CONR9R10, —CH2OH, CH2OR11, CH2OCOR11, CHO, CH(OR12)2, CH(OR13O), —COR7, CR7 (OR12)2, CR7 (OR13O), where R7 is an alkyl, cycloalkyl or alkenyl group containing 1 to 5 carbons, R8 is an alkyl group of 1 to 10 carbons or (trimethylsilyl)alkyl where the alkyl group has 1 to 10 carbons, or a cycloalkyl group of 5 to 10 carbons, or R8 is phenyl or lower alkylphenyl, R9 and R10 independently are hydrogen, an alkyl group of 1 to 10 carbons, or a cycloalkyl group of 5-10 carbons, or phenyl, hydroxyphenyl or lower alkylphenyl, R11 is lower alkyl, phenyl or lower alkylphenyl, R12 is lower alkyl, and R13 is divalent alkyl radical of 2-5 carbons.