Ethanol → 3-(tert-Butyl)-1-(4-methoxyphenyl)-1H-pyrazol-5-amine

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Reaction Steps

A mixture of 4-methoxyphenylhydrazine hydrochloride (3.5 g), 4,4-dimethyl-3-oxopentanenitrile (2.5 g), EtOH (30 mL), and AcOH (1 mL) was heated at the reflux temperature for 3 h, cooled to room temp., and poured into a mixture of Et2O (100 mL) and a 10% Na2CO3 solution (100 mL). The organic layer was washed with a saturated NaCl solution, dried (MgSO4) and concentrated under reduced pressure. The solid residue was washed with pentane to afford the desired pyrazole as a pale brown solid. (4.25 g): 1H-NMR (DMSO-d6) δ 1.18 (s, 9H); 3.78 (s, 3H); 5.02 (br s, 2H); 5.34 (s, 1H); 6.99 (d, J=8 Hz, 2H); 7.42 (d, J=8 Hz, 2H).

Provenance & Evidence