Methylhydrazine → 3-(3-chlorophenyl)-1-methyl-1H-pyrazol-4-amine

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-(3-(3-chlorophenyl)-1-(dimethylamino)-3-oxoprop-1-en-2-yl)isoindoline-1,3-dione (2.30 g, 6.48 mmol, 1 eq) in 50 mL ethanol was added N-methylhydrazine (1.4 mL, 26 mmol, 4.0 eq). The reaction mixture was stirred at 80° C. for 2 hours and then concentrated onto silica gel. The crude mixture of regioisomers was separated and purified by flash chromatography on silica gel (0 to 80% ethyl acetate in dichloromethane) to yield: 715 mg (53%) of 3-(3-chlorophenyl)-1-methyl-1H-pyrazol-4-amine LCMS (ESI) m+H=208.2; 1H NMR (400 MHz, CDCl3) δ: 7.78 (s, 1H), 7.63 (d, 1H), 7.33 (t, 1H), 7.25 (overlapping with CDCl3, 1H), 7.04 (s, 1H), 3.84 (s, 3H), and 274.6 mg (20%) of 5-(3-chlorophenyl)-1-methyl-1H-pyrazol-4-amine. LCMS (ESI) m+H=208.2; 1H NMR (400 MHz, CDCl3) δ: 7.43 (t, 1H), 7.38 (overlapping d and s, 2H), 7.27 (d, 1H), 7.23 (s, 1H), 3.76 (s, 3H).

Provenance & Evidence