Water → {4-[(E)-2-(2-chloro-6-methoxy-phenyl)-vinyl]-3-nitro-phenyl}-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of {4-[2-(2-chloro-6-methoxy-phenyl)-2-hydroxy-ethyl]-3-nitro-phenyl}-carbamic acid tert-butyl ester (0.45 g, 1.06 mmol)in THF (10 mL) was added 2,2,2-trifluoroacetic anhydride (671 mg, 3.18 mmol) at 25° C. resulting in a color change to dark blue. The reaction was allowed to stir at 25° C. for 30 min after which 8-diazabicyclo[5.4.0]undec-7-ene (0.76 g, 5.00 mmol) was added. The reaction was heated to 70° C. for 3 h and then cooled to 25° C. and poured into water. The aqueous phase was extracted three times with ethyl acetate. The combined organic layers were washed with brine and dried over magnesium sulfate. Filtration followed by concentration in vacuo gave a brown solid. Flash chromatography (90/10 hexanes/ethyl acetate) afforded {4-[(E)-2-(2-chloro-6-methoxy-phenyl)-vinyl]-3-nitro-phenyl}-carbamic acid tert-butyl ester (240 mg, 60%) as an oil.

Provenance & Evidence