1-((R)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl)-3-nitro-1H-pyrazole → (R)-1-((2,2-Dimethyl-1,3-dioxolan-4-yl)methyl)-1H-pyrazol-3-amine

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Reaction Steps

1-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl-methyl)-3-nitro-1H-pyrazole (14.5 g) was diluted in 60 mL of ethanol and 10% palladium on carbon (1.4 g) was added. The mixture was hydrogenated on a Parr apparatus at 50 psi for 16 hr. The mixture was filtered and the solvent was removed to afford the product 1-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl-methyl)-1H-pyrazol-3-ylamine (12.4 g, 98%) as a pale yellow oil. LR-ES-MS m/z calculated for C9H15N3O2 [M]+197, observed [M+H] 198; 1H NMR (300 MHz, DMSO-d6) δ ppm 1.24 (s, 3H), 1.30 (s, 3H), 3.70 (dd, J=8.5, 6.0 Hz, 1H), 3.85-4.02 (m, 3H), 4.28 (quin, J=6.0 Hz, 1H), 4.56 (s, 2H), 5.36 (d, J=2.1 Hz, 1H), 7.30 (d, J=2.1 Hz, 1H).

Provenance & Evidence