4-Fluorobenzohydrazide → (R)-N'-(2-(4-cyano-2-methyl-3-(trifluoromethyl)phenylamino)-3-hydroxy-3-methylbutanoyl)-4-fluorobenzohydrazide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

(R)-2-(4-cyano-2-methyl-3-(trifluoromethyl)phenylamino)-3-hydroxy-3-methylbutanoic acid (500 mg, 1.58 mmol) and 4-fluorobenzohydrazide (244 mg, 1.58 mmol) were mixed together in THF (20 mL) and cooled to −15° C. under N2 atmosphere. To the pre-cooled reaction mixture were added hydroxybenzotriazole (HOBT) (214 mg, 1.58 mmol), TEA (0.33 mL, 2.37 mmol) followed by N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDCI) (454 mg, 2.37 mmol). The reaction mixture was allowed to stir at −20° C. for 20 min and then at room temperature overnight. After the reaction was complete, ethyl acetate (50 mL) was added and the solution was washed with 5% citric acid (2×40 mL), 5% NaHCO3 (2×40 mL) followed by water (40 mL) and then dried (Na2SO4) to provide the crude product as a yellow solid (660 mg, 92%): 1H NMR (400 MHz, d6-acetone, δ in ppm) 9.81 (br s, 1H), 8.02-7.95 (m, 2H), 7.69-7.63 (m, 1H), 7.27-7.21 (m, 2H), 7.01-6.95 (m, 1H), 5.54 (d, J=7 Hz, 1H), 4.14 (d, J=8 Hz, 1H), 2.38 (s, 3H), 1.47 (s, 3H) and 1.43 (s, 3H).

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