反应详情

To a 250 mL, round-bottomed flask equipped with a magnetic stir bar and septum was added N′-((2R,3R)-2-(3-chloro-4-cyano-2-methylphenylamino)-3-hydroxybutanoyl)-4-cyanobenzohydrazide (0.6871 g, 2.4 mmol) followed by addition of anhydrous THF (200 mL) under an atmosphere of nitrogen. To this was then added tosyl chloride (318 mg, 1.7 mmol) followed by addition of polystyrene bound (2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine (PS-BEMP) (2.2 mmol/g loading, 2.29 g, 5.0 mmol). This mixture was allowed to stir at room temperature for a period of 16 h. The solids were then filtered off and washed with additional THF (100 mL). The filtrate was then concentrated under reduced pressure to reveal a yellow solid. This was purified via silica gel chromatography eluted with 50% EtOAc/hexanes to provide product as a white solid (138 mg, 21%). 1H NMR (500 MHz, acetone-d6, δ in ppm) 8.19 (AA′XX′, J=8.4 Hz, 2H), 7.98 (AA′XX′, J=8.5 Hz, 2H), 7.48 (d, J=8.6 Hz, 1H), 6.89 (d, J=8.7 Hz, 1H), 5.89 (d, J=8.8 Hz, 1H), 5.11 (dd, J=5.6, 8.8 Hz, 1H), 4.71 (d, J=5.9 Hz, 1H), 4.55 (m, 1H), 2.36 (s, 3H), 1.43 (d, J=6.3 Hz, 3H).

1. customTo a 250 mL, round-bottomed flask equipped with a magnetic stir bar
2. filtrationThe solids were then filtered off
3. washwashed with additional THF (100 mL)
4. concentrationThe filtrate was then concentrated under reduced pressure
5. customThis was purified via silica gel chromatography
6. washeluted with 50% EtOAc/hexanes