Water → HCID 23442457, compound

Participants

Reaction Steps

A suspension of 4-bromo-1-methyl-3-nitro-1H-pyrazole-5-carboxylic acid ((Y. A. Manaev et al., J. Gen. Chem. USSR. (Engl. Transl.), 1982, 52, 2991), 11.0 g, 43.9 mmol), p-toluidine (23.5 g, 219 mmol), and copper powder (4.0 g, 63.0 mmol) in 5% aqueous sodium carbonate (200 ml) was stirring at 100° C. for 3 h by mechanical stirrer. After cooling to room temperature, 2N sodium hydroxide (50 ml), water (100 ml), and diethyl ether (300 ml) were added to the mixture. The separated aqueous layer was washed with ether (200 ml), acidified with concentrated hydrochloric acid, and extracted with ethyl acetate (300 ml×2). The combined organic layer was dried over magnesium sulfate, and concentrated in vacuo. To the residue (9.46 g) was added phosphorus oxychloride (90 ml), and the stirring mixture was refluxed for 1 h. After cooling to room temperature, the excess phosphorus oxychloride was removed in vacuo. To the black oily residue (ca. 10 g) was added 50% acetic acid (100 ml) at 0° C., and the mixture was refluxed with stirring for 3 h. After cooling to room temperature, the solvent was removed in vacuo, and the residue was suspended with methanol. The formed solid was collected by filtration to give 5.39 g (48%) of the title compound as a yellow solid.

Provenance & Evidence