Hydrochloric Acid → 6'-((3,3-difluorocyclobutyl)methoxy)-4-methoxyspiro[cyclohexane-1,2'-inden]-1'(3'H)-imine

Participants

Reaction Steps

HCl (4 M in 1,4-dioxane, 4.13 mL, 16.5 mmol) was added to a solution of N-(5′-((3,3-difluorocyclobutyl)methoxy)-4-methoxyspiro[cyclohexane-1,2′-indene]-3′(1′H)-ylidene)-2-methylpropane-2-sulfinamide (Intermediate 18, 750 mg, 1.65 mmol) in anhydrous 1,4-dioxane (25 mL). A white precipitate formed immediately and the resulting cloudy mixture was stirred under a nitrogen atmosphere overnight. The mixture was diluted with NaHCO3 (aq.) and extracted with DCM. The organic phase was dried and concentrated, to yield 6′-((3,3-difluorocyclobutyl)methoxy)-4-methoxyspiro[cyclohexane-1,2′-inden]-1′(3′H)-imine (672 mg, 1.92 mmol). The imine, trimethyl orthoformate (0.557 mL, 5.08 mmol) and 2-propanol (5 mL) was placed into a MW tube and the mixture was heated at 60° C. in an oil bath. 2-oxopropanethioamide (Intermediate 1, 397 mg, 3.85 mmol) in MeOH (15 mL) was added and the resulting mixture was stirred overnight. The mixture was concentrated in vacuo. The product was isolated using column chromatography (0-50% EtOAc in heptane) to give 106 mg (12% yield) of the title compound. MS (ES+) m/z 435 [M+H]+.

Provenance & Evidence