Nitric Acid → 7-nitro-3-(trifluoroacetyl)-2,3,4,5-tetrahydro-1H-1,5-methano-3-benzazepine

Participants

Reaction Conditions

Reaction Steps

(Based on the method described by Coon, C. L.; Blucher, W. G.; Hill, M. E. J. Org. Chem. 1973, 25, 4243.) To a solution of trifluoromethanesulfonic acid (2.4 ml, 13.7 mmol) in CH2Cl2 (10 ml) stirred at 0° C. was slowly added nitric acid (0.58 ml, 27.4 mmol) generating a white precipitate. After 10 minutes the resulting mixture was cooled to −78° C. and treated with 1-(10-aza-tricyclo[6.3.1.02,7]dodeca-2(7),3,5-trien-10-yl)-2,2,2-trifluoro-ethanone (3.5 g, 13.7 mmol) in CH2Cl2 (15 ml) dropwise from an addition funnel over 5 minutes. The reaction was stirred at −78° C. for 30 minutes then warmed to 0° C. for 1 hour. The reaction mixture was poured into a vigorously stirred ice (100 g). The layers were separated and the aqueous layer extracted with CH2Cl2 (3×30 ml). The organic layer was combined and washed with H2O (3×30 ml). The combined organic layer was washed with saturated aqueous NaHCO3 solution (20 mL) and H2O (20 mL) then dried through a cotton plug and concentrated to give an orange oil that solidified on standing (4.2 g). Chromatography yielded pure product as a crystalline solid (3.2 g, 78%). (TLC 30% ethyl acetate/hexanes Rf 0.23). 1H NMR (400 MHz, CDCl3 8.12 (br d, J=8.0 Hz, 1H), 8.08 (br s, 1H), 7.37 (br d, J=8.0 Hz, 1H), 4.38 (br d, J=12.6 Hz, 1H), 3.94 (br d, J=12.6 Hz, 1H), 3.59 (br d, J=12.6 Hz, 1H), 3.43–3.35 (m, 2H), 3.18 (br d, J=12.6 Hz, 1H), 2.48 (m, 1H), 2.07 (d, J=10.8 Hz, 1H). GCMS m/e 300 (M+).

Provenance & Evidence