Ammonium Chloride → 5-Cyclopropyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-amine

Participants

Reaction Steps

A mixture of 128a (2.68 g, 12.9 mmol), Fe (3.6 g, 64.4 mmol) and NH4Cl (4.1 g, 77.4 mmol) in ethanol (30 mL) and water (5 mL) was heated at reflux for 2 h. After the completion of the reaction, the mixture was filtered and the solid was washed with ethanol (150 mL). The filtrate was evaporated in vacuo and the residue was extracted with methanol/methylene chloride (1/7). The combined extracts were dried over Na2SO4 and evaporated. The residue was purified on reverse phase Combi-flash to give 128b (1.8 g, 75%). MS: [M+H]+ 179.

Provenance & Evidence