Triethylamine → 2-(5-Methyl-3-trifluoromethyl-pyrazol-1-yl)-1-[4-(3-nitro-phenyl)-piperazin-1-yl]-ethanone

To a solution of (5-methyl-3-trifluoromethyl-pyrazol-1-yl)-acetic acid (1.1 g, 5.28 mmol) in DMF (10 mL) is added triethylamine (1.47 mL, 10.57 mmol), followed by 1-hydroxy-7-benzotriazole (0.755 g, 5.55 mmol) and 1-ethyl-3-(3-dimethyllaminopropyl)carbodiimide hydrochloride (1.06 g, 5.55 mmol). After stirring 15 min at RT, 1-(3-nitro-phenyl)-piperazine (1.09 g, 5.28 mmol) is added to the reaction mixture. After stirring overnight at RT, solvent is evaporated and the resulting yellow oil is dissolved in ethylacetate (20 mL), washed with saturated aqueous sodium bicarbonate solution (50 mL), and brine (50 mL). The organic layer is dried over sodium sulfate, filtered, and evaporated under reduced pressure. The crude mixture is purified by column chromatography on silica gel (cyclohexane/ethylacetate 0-80%) to give 2-(5-methyl-3-trifluoromethyl-pyrazol-1-yl)-1-[4-(3-nitro-phenyl)-piperazin-1-yl]-ethanone (1.24 g, 59%). 1H-NMR (400 MHz, MeOD): δ=2.31 (s, 3H), 3.31-3.40 (m, 2H), 3.41-3.49 (m, 2H), 3.77-3.85 (m, 4H), 5.25 (s, 2H), 6.43 (s, 1H), 7.38-7.42 (m, 1H), 7.44-7.51 (m, 1H), 7.69-7.72 (m, 1H), 7.80-7.81 (s, 1H). MS: m/z=398 (M+1).

1. stirringAfter stirring overnight at RT
2. customsolvent is evaporated
3. dissolutionthe resulting yellow oil is dissolved in ethylacetate (20 mL)
4. washwashed with saturated aqueous sodium bicarbonate solution (50 mL), and brine (50 mL)
5. dry with materialThe organic layer is dried over sodium sulfate
6. filtrationfiltered
7. customevaporated under reduced pressure
8. customThe crude mixture is purified by column chromatography on silica gel (cyclohexane/ethylacetate 0-80%)

ORD record

ord-73883b0ee95e42d5aefe9886005969ee

Source dataset

uspto-grants-2014_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08748432B2