Ruxolitinib phosphate

The Uses of Ruxolitinib phosphate

The phosphate salt of Ruxolitinib (R702000). Ruxolitinib is a selective Janus tyrosine kinase (JAK1 and JAK2) inhibitor used in the treatment of myeloproliferative neoplasms and psoriasis.

What are the applications of Application

Ruxolitinib Phosphate is a JAK1/JAK2 inhibitor

Definition

ChEBI: A phosphate salt obtained by reaction ruxolitinib with one equivalent of phosphoric acid. Used for the treatment of patients with intermediate or high-risk myelofibrosis, including primary myelofibrosis, post-polycythemia vera myelofibrosis and post-essent al thrombocythemia myelofibrosis.

Clinical Use

Ruxolitinib phosphate is a potent, selective, ATP competitive inhibitor of tyrosine-protein kinases JAK1 and JAK2 which acts by attenuating cytokine signaling and promotes apoptosis. Ruxolitinib was discovered and developed by Incyte, is marketed under the brand name Jakafi,and is approved for the treatment of patients with myelofibrosis (MF), including primary MF, post-polycythemia vera MP, and post-essential thrombocythemia MF. Ruxolitinib is also undergoing clinical evaluation against a wide variety of cancer indications including metastatic prostate cancer, pancreatic cancer, multiple myeloma, leukemia, non-Hodgkin lymphoma, and breast cancer. Additionally, ruxolitinib is being evaluated for the treatment of psoriasis and thrombocytopenia.

Synthesis

Ruxolitinib contains one chiral center, and three general strategies for its preparation have been reported.165¨C167 These include a racemic synthesis followed by chiral separation or resolution, introduction of the side chain via an aza-Michael addition of the pyrazole fragment to 3- cyclopentylpropiolonitrile and asymmetric hydrogenation of the resulting alkene, and through introduction of the side chain via an organocatalytic, asymmetric aza-Michael addition. The route described herein utilizes the first strategy as this appears to be the largest scale reported.
The synthesis was initiated by SEM protection of commercially available chloropyrrolopyrimidine 201 to provide the protected chloropyrrolopyrimidine 202 in 89% yield. Suzuki coupling of 202 with the pyrazole pinacolatoboronate 203 gave pyrazole 204 in 64% yield. aza-Michael reaction of pyrazole 204 with 3-cyclopentylacrylonitrile 205 was accomplished in the presence of DBU to furnish SEM-protected ruxolitinib 206 in 98% yield as the racemate. The desired enantiomer 207 was isolated via chiral column separation in 93.5% yield and 99.4% ee, on 100 kg scale. Removal of the SEM group was accomplished through a two step process via treatment with lithium tetrafluoroborate and aqueous ammonium hydroxide, ultimately giving rise to ruxolitinib 208 in 84% yield. The phosphate salt was then prepared by treatment with phosphoric acid. Crystallization from MeOH/i-PrOH/n-heptane gave ruxolitinib phosphate (XX) in good overall yield in 99.8% ee. Pyrazole pinacolatoboronate 203 was prepared from pyrazole 209 via iodination with N-iodosuccinimide followed by reaction with trimethyl silyl chloride to give protected iodopyrazaole 210 in high yield. Reaction of 210 with i-PrMgCl to form the corresponding Grignard reagent followed by reaction with isopropylpinacolborane 211 provided Suzuki boronate synthon 203 in 55% yield.

storage

Store at -20°C