2-Nitro-8,9-dihydro-5H-benzo[7]annulen-7(6H)-one → 2-Amino-8,9-dihydro-5H-benzo[7]annulen-7(6H)-one

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Reaction Steps

To a stirred solution of 2-nitro-5,6,8,9-tetrahydrobenzocyclohepten-7-one (0.5 g, 0.002 mol) in THF (125 mL) was added stannous chloride in conc. HCl (4 mL) over a 5 minute period. During this time the reaction mixture got very hot but not to reflux. The reaction mixture was stirred at room temperature for 2 h. The mixture continued to stir at room temperature overnight. HPLC showed no starting material remaining. The reaction mixture was concentrated in vacuo to remove all of the volatiles and the residue dissolved in water and made basic with 6N sodium hydroxide. The suspension was filtered through celite and washed well with chloroform. The organic layer was dried over magnesium sulfate, filtered and concentrated in vacuo to give 2-amino-5,6,8,9-tetrahydro-benzocyclohepten-7-one (0.32 g, 70% yield). 1HNMR (400 MHz, DMSO-d6) δ 6.87 (d, 1H, J=8 Hz), 6.46 (s, 1H), 6.38 (d, 1H, J=8 Hz), 4.83 (s, 2H), 2.68 (m, 4H), 2.44 (m, 4H).

Provenance & Evidence