| 摘要 |
Compounds of Formula I, wherein R<SUP>2 </SUP>represents C<SUB>1-6 </SUB>alkyl (optionally substituted by one or more substituents selected from -OH, halo, cyano, nitro and aryl) or aryl, wherein each aryl and aryloxy group, unless otherwise specified, is optionally substituted, and methods of preparation thereof are disclosed. |
