Dimethylformamide → HCID 18420210, compound

Participants

Reaction Conditions

Reaction Steps

Oxalyl chloride (10.2 ml, 117 mmol) was added dropwise to a suspension of 5-tert-butyl-4-nitro-1H-pyrazol-3-carboxylic acid (6 g, 28 mmol) in dichloromethane (55 ml) containing dimethylformamide (0.1 ml) under nitrogen at 0° C. The reaction was stirred at 0° C. for 0.5 hours, allowed to warm to room temperature and stirred for a further 1.5 hours. The solvent was removed under reduced pressure, the residue was azeotroped with dichloromethane (50 ml) and the residue was dissolved in dichloromethane (100 ml). Ammonia gas was bubbled into the solution for 45 minutes and the reaction was stirred under nitrogen at room temperature for 18 hours, concentrated under reduced pressure and the residue was dissolved in ethyl acetate (250 ml). After washing with water (100 ml) and brine (100 ml) the organic phase was filtered, the filtrate was dried over MgSO4 and concentrated under reduced pressure to give 5-tert-butyl-4-nitro-1H-pyrazol-3-carboxylic acid amide (4.0 g) as a light brown solid. 1H NMR (400 MHz, DMSO-D6): δ=12.90-13.08 (1H, brs), 7.78-7.86 (1H, brs), 7.49-7.60 (1H, brs), 1.30 (9H, s) (electrospray): m/z [M+H]+ 213, [M+Na]+ 235, [M−H]+ 211.

Provenance & Evidence