Oxalic Acid → 8,9-dihydro-7-[(hydroxy)(2-methyl-1-trityl-1H-imidazol-4-yl)methyl]-10-methylpyrido[1,2-a]indol-6(7H)-one

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Reaction Steps

To a solution of diisopropylamine (557 mg) in tetrahydrofuran (7.5 ml) at -70° C. under a nitrogen atmosphere was added 1.64M butyllithium in hexane (3.35 ml). After being stirred at the same temperature for 20 minutes, the mixture was treated with a solution of 8,9-dihydro-10-methylpyrido[1,2-a]indol-6(7H)-one (995 mg) in tetrahydrofuran (10 ml) over 15 minutes. The mixture was stirred at -70° C. for 40 minutes, and a solution of 2-methyl-1-trityl-1H-imidazole-4-carbaldehyde (1.76 g) in tetrahydrofuran (20 ml) was added dropwise over 15 minutes. After the mixture was stirred at -70° C. for 1 hour and at ambient temperature for 1 hour, it was diluted with water and neutralized with a aqueous solution of oxalic acid. The organic layer was separated and the aqueous layer was extracted with chloroform. The organic layers were combined and washed with brine and dried over anhydrous magnesium sulfate. After the solvent was evaporated in vacuo, the residue was subjected to a column chromatography on silica gel (20% ethyl acetate-chloroform). The fractions containing the product were combined and evaporated in vacuo. The residue was crystallized from n-hexane-ether to give 8,9-dihydro-7[(hydroxy)(2-methyl-1-trityl-1H-imidazol-4-yl)methyl]-10-methylpyrido[1,2-a]indol-6(7H)-one (2.06 g).

Provenance & Evidence