Hydrazine hydrate (1:1) → 3-(propan-2-yl)-1H-pyrazol-5-amine

Participants

Reaction Steps

To a solution of 4-methyl-3-oxopentanenitrile (15 g, 135 mmol) in EtOH (150 mL) was added hydrazine hydrate (7.30 g, 146 mmol) slowly at 0° C. The reaction mixture was heated to reflux for 4 h. Removal of EtOH under reduced pressure gave an oily residue that was dissolved in EtOAc (200 mL) and washed with freshly prepared brine (2×50 mL). The organic layer was dried over anhydrous sodium sulfate. Removal of EtOAc gave 5-isopropyl-1H-pyrazol-3-amine, Compound (ii) (10 g, 59% yield). 1H NMR (400 MHz, CDCl3) δ (ppm): 1.22 (d, 6H), 2.80-2.92 (m, 1H), 4.80 (brs, 3H), 5.41 (s, 1H).

Provenance & Evidence