Methanol → methyl 3-nitro-1H-pyrazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

A 50-mL single-neck round-bottomed flask equipped with a magnetic stirrer and reflux condenser was purged with nitrogen and charged with 5-nitro-1H-pyrazole-3-carboxylic acid (0.86 g, 5.5 mmol) and anhydrous methanol (10 mL), and the reaction mixture was cooled to 0° C. in an ice/water cooling bath. To the resulting solution thionyl chloride (1.7 g, 14.4 mmol) was added dropwise. After the addition was complete, the bath was removed, and the reaction was heated at reflux for 3 h. After this time, the reaction was concentrated to dryness under reduced pressure to afford a quantitative yield of 156a (0.94 g) as a white solid: MS (ESI−) m/z 170 (M−H).

Provenance & Evidence