4-Toluenesulfonyl chloride → 2-Chloro-4-((1r,2s)-1-(5-(4-cyanophenyl)-1,3,4-oxadiazol-2-yl)-2-hydroxypropylamino)-3-vinylbenzonitrile

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Reaction Steps

To a solution of N′-((2R,3S)-2-(3-chloro-4-cyano-2-vinylphenylamino)-3-hydroxybutanoyl)-4-cyanobenzohydrazide (0.79 g, 1.86 mmol) in anhydrous THF (200 mL) at room temperature was added 2-tert-butylamino-2-diethylamino-1,3-dimethyl perhydro-1,3,2-diazaphosphorine on polystyrene (3 mmol base/g) (2.54 g, 5.59 mmol) followed by para-toluene sulfonyl chloride (p-TSCl) (355 mg, 1.86 mmol) and the mixture was stirred for 1 h. The mixture was filtered under suction, the residue then washed with acetone (300 mL) followed by methanol (300 mL) and then concentrated to furnish a yellow oil (0.92 g). Purification by flash column chromatography [EtOAc-hexanes (3:2) as eluent] afforded the title compound as a white crystalline solid (86 mg, 11%). 1H NMR (400 MHz, d6-acetone, δ in ppm) 8.20 (d, J=9 Hz, 2H), 7.99 (d, J=9 Hz, 2H), 7.56 (d, J=9 Hz, 1H), 6.90 (d, J=9 Hz, 1H), 6.83 (dd, J=12 and 18 Hz), 6.22 (d, J=9 Hz, 1H), 5.94 (dd, J=2 and 12 Hz) 5.84 (dd, J=2 and 18 Hz), 5.19 (d, J=9 Hz, 1H), 4.68-4.60 (m, 1H) and 1.20 (d, J=7 Hz, 3H).

Provenance & Evidence