Ethylenediamine → HCID 59734937, compound

Participants

Reaction Steps

To a solution of (±)-methyl 2′-oxo-1′-{[2-(trimethylsilyl)ethoxy]methyl}-1,1′,2′,3-tetrahydrospiro[indene-2,3′-pyrrolo[2,3-b]pyridine]-5-carboxylate from Step B (3.65 g, 8.60 mmol) in CH2Cl2 (80 mL) was added CF3CO2H (40 mL, 52 mmol) and the resulting mixture was stirred at ambient temperature for 18 h, then concentrated in vacuo. The residue was dissolved in CH2Cl2 (100 mL) and treated with ethylene diamine (2.3 mL, 34.4 mmol). The reaction mixture was stirred at ambient temperature for 18 h, then diluted with saturated aqueous NaHCO3 (50 mL). The organic layer was removed and the aqueous layer was extracted further with CH2Cl2 (2×100 mL). The combined organic layers were washed with brine (50 mL), then dried over MgSO4, filtered, and concentrated in vacuo. The crude product was purified by silica gel chromatography, eluting with CH2Cl2:MeOH—97:3, to give methyl 2′-oxo-1,1′,2′,3-tetrahydrospiro[indene-2,3′-pyrrolo[2,3-b]pyridine]-5-carboxylate as a tan solid. This solid was dissolved in MeOH (22 mL) and 1 N sodium hydroxide (25.4 mL, 25.4 mmol) was added. The reaction mixture was heated at 60° C. for 18 h then allowed to cool. The mixture was acidified by addition of 6 N HCl, and the resulting precipitate was isolated by filtration, washed with H2O, and dried in vacuo to give the title compound. MS: m/z=281 (M+1).

Provenance & Evidence