Ammonia → 5-Methyl-1-(4-methylbenzyl)-1H-pyrazole-3-carboxamide

Participants

Reaction Steps

To a mechanically stirred solution of 5-methyl-1-(4-methylbenzyl)-1H-pyrazole-3-carboxylic acid (Intermediate B, 500 mg, 2.17 mmol) in dichloromethane (15 mL) was added dropwise oxalylchloride (950 μL, 10.9 mmol) and one drop DMF. After stirring at rt for 1 h, all volatiles were removed in vacuo. The crude acid chloride thus obtained was re-dissolved in dioxane (10 mL) and added dropwise to aqueous ammonia (33%, 6.4 mL) at 0° C. After the addition was complete, the reaction mixture was stirred at rt for 30 minutes. A white precipitate formed which was collected by filtration and washed with water. The title compound was obtained after drying in vacuo (436 mg, 89%): 1H NMR (400 MHz, DMSO-d6) δ 7.37 (broad s, 1H), 7.14 (d, 2H, and broad s, 1H), 7.02 (d, 2H), 6.43 (s, 1H), 5.28 (s, 2H), 2.27 (s, 3H), 2.19 (s, 3H); ES-MS m/z 230 (MH)+; HPLC RT (Method E) 1.39 min.

Provenance & Evidence