Patent ID: 8420640

Claim:
A compound of Formula Ic or a pharmaceutically acceptable salts salt thereof: wherein R 1 is selected from the group consisting of nitro, carboxylic acid, alkylcarboxylic acid, acetamide connected in either direction, N-(2-ethanol)amine, N-(2-morpholinethyl)amine, amine optionally substituted with one or more alkyl groups, amide optionally substituted with one or more alkyl groups, and alkoxy; R 2 is selected from the group consisting of carboxylic acid, alkyl, alkanoyl, alkanesulfonyl, benzenesulfonyl, phenonyl optionally substituted with any one or more of alkoxy, halogen, or alkyl groups, benzyl optionally substituted with any one or more of alkoxy, halogen, or alkyl groups, and amide optionally substituted with any one or more of alkyl or aryl groups; R 3 is selected from the group consisting of H, alkyl, furanoalkyl, thiophenealkyl, alkanoyl, phenyl optionally substituted with any one or more halogen, alkyl, or alkoxy groups, benzyl optionally substituted with any one or more halogen, alkyl, or alkoxy groups, and phenonyl optionally substituted with any one or more halogen, alkyl, or alkoxy groups; and R 4 is selected from the group consisting of H, alkyl, or phenyl optionally substituted with any one or more halogen, alkyl, or alkoxy groups.