| abstract |
A compound of formula (I) wherein X is -CH2-, -S-, -CH (OH) -, -CH (OR) -, - CH (SH) -. -CH (SR) - or a -CH (F) -; wherein R is a C1-7 alkyl; R1 is an aryl or heteroaryl; each of R2, R3, R4 and R5 independently is a hydrogen or C1-7 alkyl, or (R2 or R3) and (R4 or R5) collectively form a C4-7 cycloalkyl; and n is 0 to 3 provided that when n is 0, X is - CH2-; or one of its salts, wherein aryl refers to an aromatic carboxylic group of 6 to 14 carbon atoms having a single ring or multiple condensed rings, and wherein heteroaryl refers to a monocycle aromatic heterocycle of 4- to 7- members or a bicycle that is composed of a 4- to 7- member monocycle aromatic heterocycle, and a fused benzene ring, and wherein said heteroaryl has at least one heteroatom. |