Hydroxyamine hydrochloride → 4,5-Dimethyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-amine

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Reaction Steps

A 100-mL single-neck round-bottomed flask equipped with a reflux condenser was charged with 287h (1.63 g, 1.0 eq., 6.70 mmol), NH2OH.HCl (2.33 g, 5.0 eq., 33.5 mmol), and ethanol (50 mL). The mixture was refluxed for 2 days. It was then cooled to room temperature and concentrated under reduced pressure. The residue was purified by reverse-phase prep-HPLC to afford 287i as a yellow solid (211 mg, 19%). MS-ESI: [M+H]+ 167.1. 1H NMR (500 MHz, CDCl3) δ 5.36 (s, 1H), 4.04-4.00 (m, 1H), 3.94-3.92 (m, 1H), 3.61 (bs, 2H), 3.30 (q, J=6.5 Hz, 1H), 3.10-3.08 (m, 1H), 2.81-2.75 (m, 1H), 2.43 (s, 3H), 1.38 (d, J=6.5 Hz, 3H).

Provenance & Evidence