Hydrochloric Acid → 1-(5-chloro-2-methylphenyl)-3-methyl-1H-pyrazol-5-amine

Participants

Reaction Conditions

Reaction Steps

To a solution of (5-chloro-2-methylphenyl)hydrazine hydrochloride (1.49 g, 7.72 mmol, 1.00 equiv) in ethanol (8 mL) was added hydrogen chloride (4.0 mL, 20 mmol, 2 equiv, 5 M aqueous solution) and 3-aminocrotonitrile (0.664 g, 8.09 mmol, 1.05 equiv). The reaction mixture was stirred at 80° C. for 16 hours and then brought to neutral pH with saturated aqueous sodium bicarbonate solution. The resultant solution was extracted twice with dichloromethane, and the combined extracts were dried over magnesium sulfate, filtered, and concentrated to yield 1.41 g (82%) of 1-(5-chloro-2-methylphenyl)-3-methyl-1H-pyrazol-5-amine, which was carried forward without further purification. LCMS (ESI) m+H=222.2; 1H NMR (400 MHz, DMSO-d6) δ: 7.39 (d, 1H), 7.37 (d, 1H), 7.25 (s, 1H), 5.22 (s, 1H), 5.00 (s, 2H), 2.04 (overlapping s and s, 6H).

Provenance & Evidence