Sodium borohydride → Ammonium Hydroxide

Participants

Reaction Steps

To a stirred suspension of (7S)-2′-oxo-1′,2′,6,8-tetrahydrospiro[cyclopenta[g]quinoline-7,3′-pyrrolo[2,3-b]pyridine]-3-carbaldehyde (1.79 g, 5.68 mmol, described in Intermediate 1) in a mixture of MeOH (30 mL) and CH2Cl2 (10 mL) was added sodium borohydride (322 mg, 8.52 mmol). The resulting mixture was stirred at ambient temperature for 48 h, with additional sodium borohydride (322 mg, 8.52 mmol) added at 16 and 20 h. The solvents were removed in vacuo and the residue was partitioned between saturated aqueous NaHCO3 (100 mL) and CH2Cl2 (100 mL). The aqueous layer was extracted further with CH2Cl2 (2×100 mL). The combined organic extracts were dried over Na2SO4, filtered, and concentrated in vacuo. The crude product was purified by silica gel chromatography, eluting with a gradient of CH2Cl2:MeOH:NH4OH—100:0:0 to 95:5:1, to give the title compound. MS: m/z=318 (M+1).

Provenance & Evidence