Sodium Hydroxide → 3-Methyl-1-(2-methylphenyl)-1H-pyrazol-5-amine

Participants

Reaction Conditions

Reaction Steps

3-Aminocrotonitrile (2.00 g, 24.4 mmol) was added to a stirred solution of (2-methylphenyl)hydrazine hydrochloride (3.67 g, 23.1 mmol) in 1 M hydrochloric acid (20 mL). The reaction was heated (100° C.) for 18 h and then cooled to rt. The solution was adjusted to pH>12 using 1 M aqueous sodium hydroxide. The mixture was extracted with dichloromethane (3×20 mL), and then the combined organic extracts were washed with brine, dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. Flash chromatography of the residue over silica gel using 25-50% ethyl acetate/hexane afforded 3-methyl-1-(2-methylphenyl)-1H-pyrazol-5-amine (3.97 g, 87%) as an orange oil. 1H NMR (300 MHz, acetone-d6) δ 7.29 (m, 4H), 5.32 (s, 1H), 2.12 (s, 3H), 2.08 (s, 3H); ES-MS m/z 188.2 (MH+), HPLC RT (min) 0.79.

Provenance & Evidence