Dichloromethane → (+/-)-2-(Hydroxymethyl)-6,8-dihydrospiro[cyclopenta[g]quinoxaline-7,3'-pyrrolo[2,3-b]pyridin]-2'(1'H)-one

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Reaction Steps

To a stirred solution of 5,6-diamino-1,3-dihydrospiro[indene-2,3′-pyrrolo[2,3-b]pyridin]-2′(1′H)-one (320 mg, 1.20 mmol, described in Intermediate 13) and MgSO4 (1.06 g, 8.81 mmol) in CH2Cl2 (15 mL) and CH3OH (15 mL) was added the ethanolate of hydroxypyruvic aldehyde trimer [Evans et al., J. Am. Chem. Soc. 1938, 60, 1628-1629] (320 mg, 1.0 mmol). After 4 h, more of the ethanolate of hydroxypyruvic aldehyde trimer (340 mg, 1.1 mmol) was added and the mixture was heated to reflux for 2 h. The reaction mixture was partitioned between brine (50 mL) and EtOAc (150 mL). The organic layer was removed and the aqueous layer was extracted further with EtOAc (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—100:0 to 90:10, to give the title compound. MS: m/z=319 (M+1).

Provenance & Evidence