Methanol → 3-(3-Amino-pyrazol-1-ylmethyl)-benzoic acid methyl ester

Participants

Reaction Steps

The 3-(3-nitro-pyrazol-1-ylmethyl)-benzoic acid methyl ester (1.78 g, 6.82 mmol) was dissolved in ethyl acetate (5 mL) and methanol (5 mL) was added. While stirring, a 50% slurry of raney nickel in water (1 mL) was added followed by hydrazine (1.5 mL). Immediate effervescence was observed. The reaction continued to stir and bubble for 30 min. The reaction was passed through a plug of celite and concentrated in vacuo to give a yellow oil. The oil was taken up in ethyl acetate (100 mL), washed with water (2×20 mL), saturated aqueous brine solution (20 mL), dried over magnesium sulfate and concentrated in vacuo. Purification by ISCO flash column chromatography (Teledyne Isco RediSep Flash Column 120 g; 15% ethyl acetate/hexanes to 100% ethyl acetate/hexanes) afforded 3-(3-amino-pyrazol-1-ylmethyl)-benzoic acid methyl ester (1.09 g, 69%) as a beige solid: H1-NMR (400 MHz, DMSO-d6) δ 3.83 (3H, s), 4.57 (2H, bs), 5.09 (2H, s), 5.41 (1H, d, J=2.0 Hz), 7.44-7.46 (3H, m), 7.76 (1H, bs), 7.82-7.84 (1H, m).

Provenance & Evidence