Vla-4 antagonists

A compound of formula I:

• or a pharmaceutically acceptable salt thereof, wherein:
• A is N or N+—O−;
• X and Y are independently selected from halogen, C1-3alkyl, and C1-3alkoxy;
• R1 is selected from (1) hydrogen, (2) C1-10alkyl, (3) —(C1-10alkyl)-aryl, (4) —(C1-10alkyl)-O—C1-10alkyl, (5) —(C1-10alkyl)-OC(O)—C1-10alkyl, (6) —(C1-10alkyl)-OC(O)-aryl, (7) —(C1-10alkyl)-OC(O)O—C1-10alkyl and (8) —(C1-10alkyl)N+(C1-3alkyl)3;
• wherein alkyl is optionally substituted with one to three substituents independently selected from Ra, and aryl is optionally substituted with one to three substituents independently selected from Rb;
• R2 is hydrogen or methyl;
• R3 and R4 are independently selected from (1) hydrogen, (2) —NRdRe, (3) —NRdS(O)mRe, (4) —NRdC(O)Re, (5) —NRdC(O)ORe, and (6) —NRdC(O)NRdRe, with the proviso that R3 and R4 are not both hydrogen;
• Ra is selected from (1) —ORd, (2) —NRdS(O)mRe, (3) —NO2, (4) halogen, (5) —S(O)mRd, (6) —SRd, (7) —S(O)2ORd, (8) —S(O)mNRdRe, (9) —NRdRe, (10) —O(CRfRg)nNRdRe, (11) —C(O)Rd, (12) —CO2Rd, (13) —CO2(CRfRg)nCONRdRe, (14) —OC(O)Rd, (15) —CN, (16) —C(O)NRdRe, (17) —NRdC(O)Re, (18) —OC(O)NRdRe, (19) —NRdC(O)ORe, (20) —NRdC(O)NRdRe, (21) —CRd(N—ORe), (22) CF3, (23) —OCF3, (24) C3-8cycloalkyl, and (25) heterocyclyl;
• wherein cycloalkyl and heterocyclyl are optionally substituted with one to three groups independently selected from Rc;
• Rb is selected from (1) a group selected from Ra, (2) C1-10 alkyl, (3) C2-10 alkenyl (4) C2-10 alkynyl, (5) aryl, and (6) —(C1-10alkyl)-aryl, wherein alkyl, alkenyl, alkynyl, and aryl are optionally substituted with one to three substituents selected from a group independently selected from Rc;
• Rc is (1) halogen, (2) amino, (3) carboxy, (4) C1-4alkyl, (5) C1-4alkoxy, (6) aryl, (7) 13 (C1-4alkyl)-aryl, (8) hydroxy, (9) CF3, (10) OC(O)C1-4alkyl, (11) OC(O)NRfRg, or (12) aryloxy;
• Rd and Re are independently selected from hydrogen, C1-10alkyl, C2-10alkenyl, C2-10alkynyl, Cy and —(C1-10alkyl)-Cy, wherein alkyl, alkenyl, alkynyl and Cy are optionally substituted with one to four substituents independently selected from Rc;
• or
• Rd and Re together with the atom(s) to which they are attached form a heterocyclic ring of 4 to 7 members containing 0-2 additional heteroatoms independently selected from O, S and N—Rh, and wherein said heterocyclic ring is optionally fused with a C3-8 carbocyclic ring or is optional substituted with 1 to 4 groups independently selected from C1-10alkyl;
• Rf and Rg are independently selected from hydrogen, C1-10alkyl, Cy and —(C1-10alkyl)-Cy;
• or
• Rf and Rg together with the carbon to which they are attached form a ring of 5 to 7 members containing 0-2 heteroatoms independently selected from oxygen, sulfur and nitrogen;
• Rh is selected from Rf and —C(O)Rf;
• Cy is selected from cycloalkyl, heterocyclyl, aryl, and heteroaryl;
• and
• m is 1 or 2.