2-(3-{(3R,4R)-4-Methyl-3-[meth-yl(7H-pyrrolo-[2,3-d]pyrimidin-4-yl)amino]-piperidin-1-yl}oxetan-3-yl)aceto-nitrile monohydrate.

In the title compound, C18H24N6O·H2O, the piperidine ring adopts a chair conformation with an N-C-C-C torsion angle of 39.5 (5)° between the cis-related substituents. The pyrrole N-H group forms a water-mediated inter-molecular hydrogen bond to one of the N atoms of the annelated pyrimidine ring. The water mol-ecule connects two organic mol-ecules and is disorderd over two positions (occupancies of 0.48 and 0.52). The crystal packing shows zigzag chains of alternating organic and water mol-ecules running parallel to the a axis.