Synthesis
GENERAL STEPS: 1H-pyrazole-4-carbaldehyde (500 mg, 5.20 mmol) was dissolved in N,N-dimethylformamide (DMF, 20 mL), and 2-bromoethyl methyl ether (713 mg, 5.2 mmol) and cesium carbonate (Cs2CO3, 3.40 g, 10.4 mmol) were added in sequence. The reaction mixture was stirred at 60 °C overnight. After completion of the reaction, water (20 mL) was added to the mixture and extracted with ethyl acetate (EtOAc, 50 mL x 3). The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure to afford the target product 1-(2-methoxyethyl)-1H-pyrazole-4-carbaldehyde (520 mg, 65% yield).
References
[1] Patent: WO2018/50684, 2018, A1. Location in patent: Page/Page column 68
[2] Patent: WO2018/50686, 2018, A1. Location in patent: Page/Page column 72; 73
