Water → tert-butyl [(3E)-4-cyano-3-({[1-methyl-5-(tritylamino)-1H-pyrazol-4-yl]amino}carbonyl)-3-buten-1-yl]carbamate

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Reaction Steps

To a stirred solution of diethyl (cyanomethyl)phosphonate (704 mg) in tetrahydrofuran (20 ml) was added sodium hydride (159 mg, 60% oil suspension) under ice-cooling. The mixture was stirred for 45 minutes with warming to room temperature. tert-Butyl (4-{[1-methyl-5-(tritylamino)-1H-pyrazol-4-yl]amino}-3,4-dioxobutyl)carbamate (2 g) was added to the mixture, and the whole mixture was stirred at room temperature for 2 hours. Water was added to the mixture, and the whole mixture was extracted with ethyl acetate. The extract was washed with water and brine and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure to give a residual oil, which was triturated with a small amount of ethyl acetate and diluted with diisopropyl ether. The resulting precipitate was collected by filtration to give tert-butyl [(3E)-4-cyano-3-({[1-methyl-5-(tritylamino)-1H-pyrazol-4-yl]amino}carbonyl)-3-buten-1-yl]carbamate (1.41 g).

Provenance & Evidence