A compound of Formula I or a pharmaceutically acceptable salt thereof, wherein R 1 is a 5 membered heteroaryl group attached through either a carbon or nitrogen atom and which is optionally fused to a (C 4 -C 7)cycloalkyl, phenyl or 6 membered heteroaryl; wherein the optionally fused 5 membered heteroaryl is optionally substituted with one to four substituents each independently selected from halo, -S 2 -(C 1 -C 3)alkyl, -S-(C 1 -C 3)alkyl, hydroxy, -C NR a R b, (C 3 -C 5)cycloalkyl, cyano, phenyl which is optionally substituted with one to three halo, cyano, (C 1 -C 3)alkyl or (C 1 -C 3)alkoxy, 6 membered heteroaryl which is optionally substituted with one to three halo, cyano, (C 1 -C 3)alkyl or (C 1 -C 3)alkoxy, (C 1 -C 6)alkyl optionally substituted with one to three fluoro, or (C 1 -C 6)alkoxy optionally substituted with one to three fluoro; R a and R b are each independently H or (C 1 -C 3)alkyl; R 2 is H or methyl; R 3 is tetrazolyl, -CH 2 -tetrazolyl, -(CH 2) 2 SO 3 H or -(CH 2) 2 CO 2 H, -CH 2 CHFCO 2 H or - CH 2 CHOHCO 2 H; A 1, A 2, A 3 and A 4 are each independently CR 4 or N, with the proviso that no more than two of A 1, A 2, A 3 and A 4 are N; R 4 at each occurrence is independently H, halo, cyano, (C 1 -C 3)alkyl optionally substituted with one to three fluoro, or (C 1 -C 3)alkoxy optionally substituted with one to three fluoro; L is -X-CH(R 5)- or -CH(R 5)-X-; X is CH 2, O or NH; R 5 is (C 1 -C 6)alkyl which is optionally substituted with one to three fluoro, hydroxy or methoxy; (C 3 -C 7)cycloalkyl which is optionally substituted with one to two (C 1 -C 3)alkyl which are optionally substituted with one to three fluoro and wherein one to two carbons of the (C 3 -C 7)cycloalkyl can be replaced with a NH, N(C 1 -C 3)alkyl, O or S; or (C 3 -C 7)cycloalkyl-(C 1 -C 6)alkyl wherein the (C 3 -C 7)cycloalkyl group of said (C 3 -C 7)cycloalkyl-(C 1 -C 6)alkyl is optionally substituted with one to two (C 1 -C 3)alkyl which are optionally substituted with one to three fluoro; B 1 B 2, B 3 and B 4 are each independently CR 6 or N, with the proviso that no more than two of B 1 B 2, B 3 and B 4 are N; and R 6 at each occurrence is independently H, halo, (C 1 -C 3)alkyl optionally substituted with one to three fluoro, or (C 1 -C 3)alkoxy optionally substituted with one to three fluoro. R 1 is a 5 membered heteroaryl group attached through either a carbon or nitrogen atom and which is optionally fused to a (C 4 -C 7)cycloalkyl, phenyl or 6 membered heteroaryl; wherein the optionally fused 5 membered heteroaryl is optionally substituted with one to four substituents each independently selected from halo, -S 2 -(C 1 -C 3)alkyl, -S-(C 1 -C 3)alkyl, hydroxy, -C NR a R b, (C 3 -C 5)cycloalkyl, cyano, phenyl which is optionally substituted with one to three halo, cyano, (C 1 -C 3)alkyl or (C 1 -C 3)alkoxy, 6 membered heteroaryl which is optionally substituted with one to three halo, cyano, (C 1 -C 3)alkyl or (C 1 -C 3)alkoxy, (C 1 -C 6)alkyl optionally substituted with one to three fluoro, or (C 1 -C 6)alkoxy optionally substituted with one to three fluoro; R a and R b are each independently H or (C 1 -C 3)alkyl; R 2 is H or methyl; R 3 is tetrazolyl, -CH 2 -tetrazolyl, -(CH 2) 2 SO 3 H or -(CH 2) 2 CO 2 H, -CH 2 CHFCO 2 H or - CH 2 CHOHCO 2 H; A 1, A 2, A 3 and A 4 are each independently CR 4 or N, with the proviso that no more than two of A 1, A 2, A 3 and A 4 are N; R 4 at each occurrence is independently H, halo, cyano, (C 1 -C 3)alkyl optionally substituted with one to three fluoro, or (C 1 -C 3)alkoxy optionally substituted with one to three fluoro; L is -X-CH(R 5)- or -CH(R 5)-X-; X is CH 2, O or NH; R 5 is (C 1 -C 6)alkyl which is optionally substituted with one to three fluoro, hydroxy or methoxy; (C 3 -C 7)cycloalkyl which is optionally substituted with one to two (C 1 -C 3)alkyl which are optionally substituted with one to three fluoro and wherein one to two carbons of the (C 3 -C 7)cycloalkyl can be replaced with a NH, N(C 1 -C 3)alkyl, O or S; or (C 3 -C 7)cycloalkyl-(C 1 -C 6)alkyl wherein the (C 3 -C 7)cycloalkyl group of said (C 3 -C 7)cycloalkyl-(C 1 -C 6)alkyl is optionally substituted with one to two (C 1 -C 3)alkyl which are optionally substituted with one to three fluoro; B 1 B 2, B 3 and B 4 are each independently CR 6 or N, with the proviso that no more than two of B 1 B 2, B 3 and B 4 are N; and R 6 at each occurrence is independently H, halo, (C 1 -C 3)alkyl optionally substituted with one to three fluoro, or (C 1 -C 3)alkoxy optionally substituted with one to three fluoro.