1-Methyl-4-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaboralan-2-yl)pyridine-2-yl]piperazine

Uses

1-Methyl-4-[5-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)pyridin-2-yl]piperazine is used to prepare yrazolopyridine and indazoles as histone lysine methyltransferase EZH2 inhibitors. It is also used to synthesize tetrahydropyrido pyrazines as anaplastic lymphoma kinase inhibitors.

Synthesis

Using 1-(5-bromopyridin-2-yl)-4-methylpiperazine (1.5 g, 5.9 mmol), bis(pinacolato)diboron (1.6 g, 6.5 mmol), potassium acetate (1.8 g, 18 mmol), and Pd(dppf)2Cl2[CH2Cl2] (0.73 g, 0.89 mmol) as raw materials, the mixture was dissolved under nitrogen protection in DMSO (20 mL) and the reaction was stirred at 80 °C overnight. After completion of the reaction, the mixture was diluted with water and extracted with ethyl acetate (EA). The organic phases were combined and concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (eluent: petroleum ether/ethyl acetate, v/v=3 to pure ethyl acetate) to afford the target product, 6-(4-methyl-1-piperazinyl)pyridine-3-boronic acid pinacol ester (1.0 g, 56% yield) as a brown solid. Mass spectrometry (MS) analysis showed m/z 304 (M+H)+.

References

[1] Patent: WO2016/73956, 2016, A1. Location in patent: Paragraph 00361
[2] Patent: EP2719697, 2014, A1. Location in patent: Paragraph 0169; 0172; 0173