Patent ID: 8008325

Claim:
A compound of formula (I): wherein: R 1 is hydrogen; R 2 is —SH, —S—C(O)—R 8 , —P(O)(OR 5 ) 2 , —P(O)(OR 5 )R 6 , —P(O)(OR 5 )—R 7 —N(R 6 ) 2 , —P(O)(OR 5 )—R 7 —C(O)—R 8 , —P(O)(OR 5 )—R 7 —N(R 5 )—C(O)OR 8 , or —P(O)(OR 5 )—R 7 —N(R 5 )—C(S)—N(R 6 ) 2 ; R 3 is tetrazole, —C(O)OR 6 , or —C(O)O—R 7 —OC(O)R 5 ; R 4 is phenyl substituted by one or more substituents selected from the group consisting of alkyl, halo, haloalkyl, haloalkoxy, mercapto, alkylthio, phenyl, cycloalkyl, nitro, cyano, —OR 6 , —N(R 6 ) 2 , —R 7 —N(R 6 ) 2 , —N(R 6 )—C(O)OR 8 , —R 7 —N(R 6 )—C(O)OR 8 , —N(R 6 )—C(O)—R 6 , —R 7 —N(R 6 )—C(O)—R 6 , —C(O)—N(R 6 ) 2 , —C(O)—R 7 —N(R 6 ) 2 , —N(R 5 )—C(NR 5 )—N(R 5 ) 2 , —N(R 5 )—C(O)—N(R 6 ) 2 and —N(R 5 )—C(O)—R 7 —N(R 6 2 ); each R 5 is independently hydrogen, alkyl or aralkyl; each R 6 is independently hydrogen, alkyl, alkenyl, alkynyl, aryl, aralkyl or aralkenyl; each R 7 is independently cycloalkylene (optionally substituted by alkyl), a straight or branched alkylene chain (optionally substituted by hydroxy, mercapto, alkylthio, aryl, cycloalkyl, —N(R 6 ) 2 , —C(O)OR 6 , or —C(O)N(R 6 ) 2 ), or a straight or branched alkenylene chain (optionally substituted by hydroxy, mercapto, alkylthio, aryl, cycloalkyl, —N(R 6 ) 2 , —C(O)OR 6 , or —C(O)N(R 6 ) 2 ); and each R 8 is independently alkyl, alkenyl, aryl, aralkyl or aralkenyl; provided that when R 3 is —C(O)OH or when R 4 is a substituted phenyl, R 2 can not be —P(O)(OR 5 )—R 7 —N(H)—C(O)OR 8 ; as a single stereoisomer, a mixture of stereoisomers, or as a racemic mixture of stereoisomers; or a pharmaceutically acceptable salt thereof.