Trifluoroacetic acid → HCID 86724100, compound

Participants

Reaction Steps

To a solution of 1-methyl-5-nitro-1H-pyrazole-3-carbohydrazide (3.81 g, 20.6 mmol) in DCM (30 mL) was added 2,2,2-trifluoroacetic acid (4 mL, 51.9 mmol). The mixture was stirred for about 2 h then concentrated under reduced pressure. To the residue was added triethoxymethane (31.4 mL, 206 mmol) and the mixture was refluxed for about 24 h. The reaction was cooled to ambient temperature and continued to stir for about 16 h. The reaction mixture was concentrated under reduced pressure and the material was partitioned between DCM (25 mL) and saturated NaHCO3 (10 mL). The organic layer was separated and the aqueous layer was back extracted with DCM (25 mL). The combined organic layers were washed with brine (10 mL), dried over MgSO4, filtered and concentrated under reduced pressure and triturated with ether (2×30 mL).

Provenance & Evidence