PF-06447475

Uses

PF 06447475 is a highly potent LRRK2 kinase inhibitor. Highly selective, and mobile, it is used in the treatment of Parkinson’s disease which has been linked to Leucine rich repeat kinase 2 (LRRK2) enzymes.

Synthesis

1. In a dry reaction flask, morpholine (871 mg, 10 mmol) and N,N-diisopropylethylamine (2.6 g, 20 mmol) were sequentially added to a solution of n-butanol (100 mL) containing 3-(4-chloro-7H-pyrrolo[2,3-d]pyrimidin-5-yl)benzonitrile (2.5 g, 9.8 mmol). 2. The reaction mixture was heated to reflux with continuous stirring for 3 hours. 3. Upon completion of the reaction, the solvent was removed by rotary evaporator under reduced pressure. 4. The residue was purified by silica gel column chromatography with the eluent being a solvent mixture of ethyl acetate and petroleum ether (1:1, v/v). 5. After collection of the target fraction, the target fraction was further recrystallized using ethyl acetate and tert-butyl methyl ether to give the white solid product 3-(4-morpholino-7H-pyrrolo[2,3-d]pyrimidin-5-yl)benzonitrile. 6. Yield: 770 mg, 2.52 mmol, 26%. 7. 7. Product characterization: LCMS m/z 306.0 [M + H]+. 1H NMR (400 MHz, DMSO-d6) δ 12.34 (br s, 1H), 8.41 (s, 1H), 7.99-8.02 (m, 1H), 7.89 (br d, J = 8 Hz, 1H), 7.76 (br d, J = 7.5 Hz, 1H), 7.71 (s, 1H), 7.81 (s, 1H), 7.82 (br d, J = 7.5 Hz, 1H). 7.71 (s, 1H), 7.68 (dd, J = 7.8, 7.8 Hz, 1H), 3.44-3.50 (m, 4H), 3.11-3.17 (m, 4H).

Enzyme inhibitor

This potent, brain penetrant and selective LRRK2 inhibitor (FW = 305.44 g/mol; CAS 1527473-33-1), also named 3-[4-(4-morpholinyl)-7Hpyrrolo[2,3-d]pyrimidin-5-yl]benzonitrile, targets Leucine-Rich Repeat Kinase 2, IC50 = 3 nM, (encoded by the PARK8 gene), which phosphorylates Akt1 (Ser-473), suggesting that Akt1 is a convincing candidate for the physiological substrate of LRRK2. Diseaseassociated mutations forms of LRRK2 (including Arg-1441-Cys, Gly-2019- Ser, and Ile-2020-Thr) exhibit reduced interaction with, and phosphorylation of, Akt1, a finding that suggests a possible mechanism for the neurodegeneration caused by LRRK2 mutations. Therapeutic approaches to slow or block the progression of Parkinson disease (PD) do not exist. Given that genetic and biochemical studies implicate α-synuclein and leucine-rich repeat kinase 2 (LRRK2) in late-onset PD. In wild-type rats as well as transgenic [Gly-2019-Ser]-LRRK2 rats that were injected intracranially with adeno-associated viral vectors expressing human α- synuclein in the substantia nigra, those expressing [Gly-2019-Ser]-LRRK2 show exacerbated dopaminergic neurodegeneration and inflammation in response to the overexpression of α-synuclein. Both neurodegeneration and neuroinflammation associated with [Gly-2019-Ser]-LRRK2 expression were mitigated by PF-06447475, which provided neuroprotection in wildtype rats. There are no adverse pathological indications in the lung, kidney, or liver of rats treated with PF-06447475. Pharmacological inhibition of LRRK2 is well tolerated for a 4-week period of time in rats and can counteract dopaminergic neurodegeneration caused by acute α-synuclein overexpression

in vivo

References

[1] Patent: WO2014/1973, 2014, A1. Location in patent: Page/Page column 56; 57; 58
[2] Journal of Medicinal Chemistry, 2015, vol. 58, # 1, p. 419 - 432