Sulfuric acid magnesium salt (1:1) → 1-(2-Methoxyethyl)-N-methyl-4-nitro-1H-pyrazole-3-carboxamide

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Reaction Steps

To a solution of methylamine hydrochloride (2.0 g, 25 mmol) at rt in dioxane (60 ml) was added trimethyaluminium (2 M in toluene, 12.3 ml, 25 mmol) and stirred for 2 hrs at rt. Then 1-(2-methoxyethyl)-4-nitro-1H-pyrazole-3-carboxylic acid ethyl ester (2.0 g, 8.0 mmol; example 4, step 2) was added. The mixture was heated to 100° C. and stirring was continued overnight. The mixture was cooled to rt, then 2 ml water was added and stirring was continued for 15 min. Some MgSO4 was added and stirring was continued for 15 min. The mixture was filtered, washed with CH2Cl2 and concentrated. The crude product was purified by silica gel chromatography using a cyclohexane/EtOAc gradient, providing the title compound (302 mg, 16%) as orange oil.

Provenance & Evidence