3,5-Bis(trifluoromethyl)benzylamine → (+/-)-9-(3,5-bis-trifluoromethyl-benzylamino)-2,3,6,7,8,9-hexahydro-1H-5-aza-cyclohepta[f]indene-5-carboxylic acid isopropyl ester

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Reaction Steps

Add 3,5-bis(trifluoromethyl)benzylamine (187 mg, 0.77 mmol) followed by titanium isopropoxide (835 mg, 2.94 mmol) to 9-oxo-2,3,6,7,8,9-hexahydro-1H-5-aza-cyclohepta[f]indene-5-carboxylic acid isopropyl ester (200 mg, 0.7 mmol) at room temperature under an atmosphere of nitrogen and stir the solution for 3 days. Add methanol (3 mL) and sodium borohydride (40 mg, 1.05 mmol) and stir the mixture under nitrogen at room temperature for 16 h. Add sodium bicarbonate saturated solution, filter through Celite® and wash the residue with ethyl acetate. Separate organic layer, extract aqueous with ethyl acetate. 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 silica cartridge, eluting with hexanes/ethyl acetate 9:1, to afford (+/−)-isopropyl-9-(3,5-bis-trifluoromethyl-benzylamino)-2,3,6,7,8,9-hexahydro-1H-5-aza-cyclohepta[f]indene-5-carboxylate (220 mg).

Provenance & Evidence