l,2-SUBSTITUTED 3-OXOPYRAZOLIDINE DERIVATIVES AS PROSTAGLANDIN E2 RECEPTOR 4 (EP4) AGONISTS FOR THE TREATMENT OF GASTROINTESTINAL AND PULMONARY DISEASES

A compound of the Formula I:

• or a pharmaceutically acceptable salt solvate, hydrate, tautomer or optical isomer thereof, wherein;
• A is OR′, C(O)R′, CO2R′, C(O)N(R′)2, C(O)N(R′)S(O)2R3, S(O)2R′, S(O)2OR′, SO2N(R′)2, C1-8 alkyl, cycloalkyl, heterocycloalkyl, aryl, or heteroaryl;
• X is halo, OR′, COOR′, or C1-6 alkyl;
• L and L′are each independently a C2-4 alkylene;
• R1 is H, halo, CN, NO2, OR′, SR′, COOR′, C1-6 alkoxy, or C1-6 alkyl;
• R2 is OR′, OC(O)R3, OC(O)OR3, CO2R′, CON(R′)2, SO2N(R′)2, SO2R3, OSO2R3, or OSO2N(R′)2;
• R3 is C1-6 alkyl, C3-6 cycloalkyl, or a phenyl;
• R′ is H, C1-6 alkyl, or C3-6 cycloalkyl;
• and
• n is 0, 1, 2, or 3;
• wherein at each occurrence, alkyl, alkylene, alkoxy, and cycloalkyl are each optionally and independently substituted with up to 3 instances of OH, SH, CN, NO2, COOH, halo, or COOC1-4 alkyl;
• wherein at each occurrence, heterocycloalkyl, aryl, and heteroaryl are each optionally and independently substituted with up to 3 instances of OR′, SR′, CN, NO2, CO2R′, halo, C1-4 alkyl, or oxo.