Dimethylformamide → methyl 5-(3-chloropropoxy)-1-methyl-1H-pyrazole-3-carboxylate

Cesium carbonate (2.08 g, 6.4 mmol) and 1-bromo-3-chloropropane (1.6 ml) were added to a DMF solution (5 ml) of methyl 5-hydroxy-1-methyl-1H-pyrazole-3-carboxylate (0.83 g, 5.3 mmol) and the mixture was stirred at room temperature for 21 hours. Water was added to the reaction solution, which was then extracted with ethyl acetate. The organic phase was washed with water and dried over magnesium sulfate. The reaction solution was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=100:1→4:1). The purified product was concentrated to dryness under reduced pressure to obtain methyl 5-(3-chloropropoxy)-1-methyl-1H-pyrazole-3-carboxylate (1.17 g) as white solid.

1. extractionwas then extracted with ethyl acetate
2. washThe organic phase was washed with water
3. dry with materialdried over magnesium sulfate
4. concentrationThe reaction solution was concentrated under reduced pressure
5. customThe residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=100:1→4:1)
6. concentrationThe purified product was concentrated to dryness under reduced pressure

ORD record

ord-ba4f08eb8be347e284aea66939f5277a

Source dataset

uspto-grants-2011_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08071600B2