Patent ID: 7687506

Claim:
A compound having the formula (IA): in which R 2 is hydrogen or a group having the formula —(CH 2 ) b R b wherein b is 0 or an integer from 1 to 3 and R b is an aromatic, heterocyclic or cyclical aliphatic group optionally substituted with one or more groups selected from lower alkyl, halogen, substituted alkyl, nitro, alkoxy, phenoxy, and sulfonamido; R 4 is an aliphatic, aromatic, or heterocyclic group optionally substituted with one or more polar groups, which polar group may be protected or unprotected; R 5 is hydrogen, alkoxy, alkylthio, alkylamino, aryloxy, arylthio, or arylamino; and E is —(CH 2 ) m COR′, —CO(CH 2 ) n R′, —C(O)C(O)R′, or an olefin attached to an electron withdrawing group, wherein m and n are independently 0 or an integer from 1 to 6, wherein R′ is independently hydrogen, halogen, cyano, amino, alkyl, substituted alkyl, aryl, substituted aryl, heterocyclic group or substituted heterocyclic group, and wherein the substituted alkyl, substituted aryl and substituted heterocyclic group are independently substituted with halo, hydroxyl, thiol, nitro, amino, amido, alkoxy, haloalkoxy, alkylenedioxy, alkyl, haloalkyl, or hydroxyalkyl.