N-BETA-氨乙基-GAMMA-氨丙基甲基二甲氧基硅烷 → 2-Chloro-4-((1R,2S)-2-hydroxy-1-(5-(3-methoxyphenyl)-1,3,4-oxadiazol-2-yl)propylamino)-3-methylbenzonitrile

To a 100 mL round bottom flask was added N′-((2R,3S)-2-(3-chloro-4-cyano-2-methylphenylamino)-3-hydroxybutanoyl)-3-methoxybenzohydrazide (Intermediate 6a) (441 mg, 1.1 mmol) was added THF (90 mL) and stirred at room temperature. PS-BEMP (1.45 g, 3.2 mmol base) was added to the solution followed by slow addition of p-TSCl (208 mg, 1.1 mmol). The reaction mixture was stirred for 2 h and the progress of the reaction was monitored by TLC. After the completion of the reaction, the BEMP reagent was filtered off, washed with methanol (100 mL), and the resulting solution was concentrated to obtain the crude material. The crude material was chromatographed on silica gel with hexanes:EtOAc (2:8) to get the purified product (232 mg, 55%). 1H NMR (400 MHz, d6-acetone, δ in ppm) 7.42 (m, 1H), 7.33 (m, 3H), 7.01 (m, 1H), 6.50 (d, J=8.7 Hz, 1H), 5.37 (d, J=8.5 Hz, 1H), 4.72 (m, 1H), 4.62 (m, 1H), 3.94 (br s, 1H), 3.80 (s, 3H), 2.37 (s, 3H), 1.43 (d, J=6.4 Hz, 3H).