Trifluoroacetic anhydride → 1,3-Diethyl-8-methoxy-7-nitro-1,3,4,5-tetrahydro-benzo[d]azepin-2-one

Participants

Reaction Conditions

Reaction Steps

1,3-Diethyl-8-methoxy-1,3,4,5-tetrahydro-benzo[d]azepin-2-one (564 mg, 2.28 mmol) was dissolved in 1 ml of anhydrous MeCN. The reaction was cooled to 0° C. and trifluoroacetic anhydride (3.00 mL, 21.2 mmol) and Potassium nitrate (230 mg, 2.28 mmol) were charged. The reaction was stirred for 1.5 h and then the reaction was basified with 1-2 ml of 30% NaOH solution and allowed to stir for 1 h. Pour reaction into 75 ml water and extract with 3×30 ml portions of methylene chloride. Dry the combined organic over magnesium sulfate and evaporate. Product is a yellow brown oil (625 mg). Crude material was chromatographed on a 40 g Isco column using 30-50% EtOAc in hexanes as the eluent to yield 1,3-diethyl-8-methoxy-7-nitro-1,3,4,5-tetrahydro-benzo[d]azepin-2-one (205 mg, 31%) as a tan waxy solid as a mixture of diastereomers.

Provenance & Evidence