Patent ID: 8710261

Claim:
A compound of Formula Ic: or racemates, enantiomers, diastereomers, or pharmaceutically acceptable salts thereof wherein: n is an integer from 1 to 5; R 1 is alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, aralkyl, alkoxy, aryloxy, alkenyloxy or alkynyloxy, each of which can be optionally substituted; R 2a is NR 4 R 5 , —NHC(═Y)R 4 , —NHC(═Y)NR 5 R x , —NHC(═O)OR 4 , —NHSO 2 R 4 , amidino or guanidino; wherein: Y is oxygen or sulphur; R 4 is alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heterocyclyl, heteroaryl, aralkyl, heteroarylalkyl, heterocyclylalkyl or cycloalkylalkyl; m is an integer 0-2; R 5 is hydrogen or R 4 ; or R 4 and R 5 together may optionally form a heterocyclic ring R x is R 4 or —SO 2 N(R 4 ) 2 ; and A is OH, OR 4 , —OC(═O)NR 4 R 5 , O-acyl, NH 2 , NR 4 R 5 , —NHC(═Y)R 4 , —NHC(═Y)NR 5 R x , NHC(═O)OR 4 , NHSO 2 R 4 .