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

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-cyanobenzohydrazide (301 mg, 1.87 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) (230 mg, 1.70 mmol), TEA (0.36 mL, 2.55 mmol) followed by N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDCI) (489 mg, 2.55 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 (790 mg, 99%): 1H NMR (400 MHz, d6-acetone, δ in ppm) 9.92 (br s, 1H), 9.49 (br s, 1H), 7.99 (d, J=9 Hz, 2H), 7.81 (d, J=9 Hz, 2H), 7.42 (d, J=9 Hz, 1H), 6.61 (d, J=9 Hz, 1H), 6.53 (dd, J=12 and 18 Hz, 1H), 5.99 (d, J=9 Hz, 1H), 5.73 (dd, J=2 and 12 Hz, 2H), 5.64 (dd, J=2 and 18 Hz), 4.29-4.22 (m, 1H), 4.01-3.99 (m, 1H) and 1.20 (d, J=7 Hz, 3H).

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