Hydrochloric Acid → 1-(6-methylpyridin-3-yl)-3-(trifluoromethyl)-1H-pyrazol-5-amine

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Reaction Steps

A mixture of 5-hydrazinyl-2-methylpyridine hydrochloride (5.0 g, 31 mmol) and 4,4,4-trifluoro-3-oxo-butyronitrile (9.0 g, 65 mmol) in ethanol (50 mL) was treated with cone HCl (5.0 mL, 60 mmol) and the resultant mixture was heated to reflux overnight. The solvent was removed in vacuo and the residue was dissolved in EtOAc and neutralized with saturated Na2CO3 solution. The organic layer was dried (Na2SO4), concentrated in vacuo and purified by pre-HPLC to give 2-(6-methyl-pyridin-3-yl)-5-trifluoromethyl-2H-pyrazol-3-ylamine (1.3 g, 10% yield over 2 steps). 1HNMR (400 MHz, CDCl3) δ 9.17 (d, J=1.6 Hz, 1 H), 8.40 (dd, J=8.4, 2.4 Hz, 1 H), 7.62 (d, J=8.4 Hz, 1 H), 5.97 (s, 1 H), 2.80 (s, 3 H); MS (ESI) m/z: 243.2 (M+H+).

Provenance & Evidence