Methane → 6'-(5-Methylpyridin-3-yl)trispiro[cyclobutane-1,2'-chromene-4',4''-[1,3]oxazole-3',3'''-oxetan]-2''-amine

Participants

Reaction Conditions

Reaction Steps

A mixture of di-tert-butyl (6′-bromotrispiro[cyclobutane-1,2′-chromene-4′,4″-[1,3]oxazole-3′,3′″-oxetan]-2″-yl)imidodicarbonate (300 mg, 0.531 mmol), 5-methylpyridine-3-boronic acid (145 mg, 1.06 mmol), bis(triphenylphosphine)palladium(II) dichloride (37 mg, 0.053 mmol) and Na2CO3 (169 mg, 1.59 mmol) in dioxane-H2O (4:1, 6.0 mL) was stirred for 1 hour at 100° C. To the mixture was added charcoal and the mixture was stirred for 10 minutes at 50° C. The mixture was filtered through celite pad (eluted with EtOAc) and the filtrate was washed with H2O and brine. The organic layer was dried over MgSO4 and filtered, and the filtrate was concentrated under reduced pressure. To the residue were added toluene (3.0 mL) and silica gel (neutral; 900 mg), and the mixture was stirred for 3 hours at 120° C. After concentration of the reaction mixture at reduced pressure, the residue was purified with column chromatography on silica gel (CHCl3-EtOH, a linear gradient of EtOH from 0 to 20%) to afford 6′-(5-methylpyridin-3-yl)trispiro[cyclobutane-1,2′-chromene-4′,4″-[1,3]oxazole-3′,3′″-oxetan]-2″-amine (151 mg).

Provenance & Evidence