3-Hydroxy-5-oxo-4a,5,6,7,8,8a-hexahydro-naphthalene-2-carboxylic acid methyl ester → 8-Bromo-10-fluoro-2-hydroxy-9-trifluoromethyl-5,11-dihydro-6H-benzo[a]carbazole-3-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A sample of (4-Bromo-2-fluoro-3-trifluoromethyl-phenyl)-hydrazine hydrochloride (199 mg, 642 μmol) and 3-hydroxy-5-oxo-4a,5,6,7,8,8a-hexahydro-naphthalene-2-carboxylic acid methyl ester (141 mg, 642 μmol) are treated with anhydrous ZnCl2 (219 mg, 1.60 mmol) and acetic acid (8 mL). The reaction is heated to 105° C. overnight. After cooling to room temperature, the solvent is removed by rotary evaporation. The reaction is then treated with ethyl acetate and extracted with 1 M HCl twice. The organics are then dried over MgSO4 and filtered. The residue is then crystallized from methanol to afford 194 mg of the title compound as a white solid; 1H NMR (400 MHz, DMSO-d6) δ 12.58 (s, 1H), 10.56 (s, 1H), 7.93 (s, 1H), 7.73 (s, 1H), 7.54 (s, 1H), 3.92 (s, 3H), 3.00-2.88 (m, 4H); ESIMS m/z for (M++H+) calculated 458.0, found 458.0.

Provenance & Evidence