Pyridine 1-oxide, 2-((7-cyclopentyl-6-(dimethylcarbamoyl)-7H-pyrrolo[2,3-d]pyrimidin-2-yl)amino)-5-(piperazin-1-yl); 2-((7-Cyclopentyl-6-(dimethylcarbamoyl)-7H-pyrrolo[2,3-d]pyrimidin-2-yl)amino)-5-(piperazin-1-yl)pyridine 1-Oxide ;