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

Participants

Reaction Steps

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.

Provenance & Evidence