5-(Bromomethyl)-1-methyl-3-nitro-1H-pyrazole → 5-(methoxymethyl)-1-methyl-3-nitro-1H-pyrazole

A 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer and reflux condenser was charged with CH3OH (50 mL), 5-(bromomethyl)-1-methyl-3-nitro-1H-pyrazole 156d (8.8 g, 40 mmol) and CH3ONa (4.3 g, 80 mmol). The reaction mixture was heated at reflux for 2 h. After this time the reaction was cooled to room temperature and concentrated. The residue was partitioned between ethyl acetate (60 mL) and water (60 mL). The aqueous layer was separated and extracted with ethyl acetate (50 mL×2). The organic layers were combined, washed with brine (50 mL), and dried over sodium sulfate. The drying agent was removed by filtration and the filtrate was concentrated under reduced pressure to afford 176a as a yellow oil (6.1 g, 90%). LCMS: [M+H]+ 172.

1. customA 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer
2. temperaturereflux condenser
3. temperatureThe reaction mixture was heated
4. temperatureat reflux for 2 h
5. concentrationconcentrated
6. customThe residue was partitioned between ethyl acetate (60 mL) and water (60 mL)
7. customThe aqueous layer was separated
8. extractionextracted with ethyl acetate (50 mL×2)
9. washwashed with brine (50 mL)
10. dry with materialdried over sodium sulfate
11. customThe drying agent was removed by filtration
12. concentrationthe filtrate was concentrated under reduced pressure

ORD record

ord-f858a25006bc4c5f91fd7ba6d131821f

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08618107B2