Nitric Acid → 7-Nitro-2,3,4,5-tetrahydro-1H-benzo[D]azepine

To a cooled (0° C.) solution of trifluoroacetic acid (67.2 ml, =869.38 mmol), 2,3,4,5-Tetrahydro-1H-benzo[d]azepine (18 g, 122.44 mmol) was added drop-wise over a period of 20 min. To this, concentrated sulphuric acid (23.4 ml, 440.78 mmol) was added over a period of 45 min at 0° C., and the mixture was stirred for an additional 30 minutes. To this reaction mixture, concentrated nitric acid (8.1 ml, 192.23 mmol) was added drop-wise at 0° C. over a period of 1 h, followed by stirring at room temperature for 2 h. To the reaction mixture, ethyl acetate (250 ml) was added drop-wise at 0° C. The resulting precipitate was filtered and washed with ethyl acetate (100 ml). The crude solid product was added to chloroform (250 ml), washed with 10% sodium hydroxide solution (150 ml), dried over Na2SO4, and concentrated to give the sub-title compound as a light yellow solid (17.4 g). 1H NMR (300 MHz, DMSO-d6) δ 7.99-7.93 (m, 2H); 7.38 (d, J=8.1 Hz, 1H); 2.98-2.94 (m, 4H); 2.79-2.76 (m, 4H); MS: ESI (positive): 193 (M+H).

1. additionwas added drop-wise over a period of 20 min
2. stirringby stirring at room temperature for 2 h
3. filtrationThe resulting precipitate was filtered
4. washwashed with ethyl acetate (100 ml)
5. additionThe crude solid product was added to chloroform (250 ml)
6. washwashed with 10% sodium hydroxide solution (150 ml)
7. dry with materialdried over Na2SO4
8. concentrationconcentrated

ORD record

ord-08547f66732842eab8664d07a1c5848d

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09284277B2