HCID 86716575, compound → HCID 71116130, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 1-{[(2R,3R,75)-7-methyl-2,3-diphenyl-1,4-dioxaspiro[4.5]dec-7-yl]methyl}-1H-benzimidazole-6-carbonitrile (235 g, 508 mmol) in formic acid (1948 mL) was heated to 70° C. for 18 h, then the solution was concentrated under reduced pressure, and diluted with sat. NaHCO3 until it was basic. The resulting mixture was extracted with DCM (3×), and the combined extracts were washed with brine and then concentrated under reduced pressure. To the residue was added EtOAc (1 L) and then it was concentrated at 60° C. to a volume of approximately 750 mL. The slurry was then allowed to cool. Once solids started to form, the slurry was slowly diluted with 500 mL of hexanes and the temperature was raised to about 60° C. An additional 500 mL of hexanes was slowly added and the temperature was raised to reflux (about 68° C.). Once at reflux, heating was stopped, and the solution was allowed to cool to RT and stir for 5 days. Then the slurry was filtered, the solids were washed with hexanes and dried under reduced pressure to give 105.5 g of product (78% yield). The filtrate was concentrated and loaded onto silica gel and purified on a 220 g column (like a plug of silica) using vacuum to pull solvent through the column, and eluted with 500 mL of DCM, then 1 L of 50% EtOAc/DCM, then 1 L of 100% DCM, then 1 L each of 2.5%, 5%, 7.5%, and 10% MeOH/DCM. Fractions were collected in 1 L portions. Fractions containing product were concentrated to afford an additional 20.4 g (15% yield) of product. MS (m/z) 268.1 (M+H+).

Provenance & Evidence