Hydrochloric Acid → (+/-)-6-[Acetyl-(3,5-bis-trifluoromethyl-benzyl)-amino]-2,3,6,7,8,9-hexahydro-1H-10-aza-cyclohepta[e]indene-10-carboxylic acid isopropyl ester

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Reaction Steps

Add 3,5-bis(trifluoromethyl)benzylamine (349 mg, 1.15 mmol) followed by titanium isopropoxide (414 mg, 1.46 mmol) to 6-Oxo-2,3,6,7,8,9-hexahydro-1H-10-aza-cyclohepta[e]indene-10-carboxylic acid isopropyl ester (300 mg, 1.04 mmol) at room temperature under an atmosphere of nitrogen and stir the solution for 14 h. Add methanol (4.3 mL) and sodium borohydride (59 mg, 1.56 mmol) and stir the mixture under nitrogen at room temperature for 45 min. Add 0.1M NaOH, stir for 30 min. Filter through celite and wash the residue with AcOEt. Separate organic layer, extract aqueous with AcOEt. Wash organic layer with brine and dry the organic layers over anhydrous sodium sulfate. Filter and remove the solvent under reduced pressure. Purify the residue by flash chromatography, eluting with hexanes/ethyl acetate, to afford (+/−)-6-(3,5-Bis-trifluoromethyl-benzylamino)-2,3,6,7,8,9-hexahydro-1H-10-aza-cyclohepta[e]indene-10-carboxylic acid isopropyl ester (443 mg, 83%). Add acetic anhydride (0.24 mL, 2.52 mmol) dropwise to a solution of the amine (184 mg, 0.36 mmol) and pyridine (0.25 mL, 3.06 mmol) in dichloromethane (3.1 mL). Stir under nitrogen at room temperature for 14 h. Add 1 M hydrochloric acid and extract with dichloromethane. Dry the organic layer over anhydrous sodium sulfate, filter and remove the solvent under reduced pressure. Purify the residue by flash chromatography, eluting with hexanes/ethyl acetate, to afford the title compound (149 mg, 74%); MS (ES+): 557 (M+H).

Provenance & Evidence