Sodium Carbonate → di-tert-butyl [6'-(3,6-dihydro-2H-pyran-4-yl)dispiro[1,3-oxazole-4,4'-chromene-3',3''-oxetan]-2-yl]imidodicarbonate

Participants

Reaction Conditions

Reaction Steps

A mixture of di-tert-butyl (6′-bromodispiro[1,3-oxazole-4,4′-chromene-3′,3″-oxetan]-2-yl)imidodicarbonate (300 mg, 0.571 mmol), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,6-dihydro-2H-pyran (360 mg, 1.71 mmol), bis(triphenylphosphine)palladium(II) dichloride (40.1 mg, 0.057 mmol) and Na2CO3 (182 mg, 1.71 mmol) in dioxane (3.6 mL) and water (0.9 mL) was stirred for 1 hour at 100° C. The mixture was cooled down to ambient temperature and partitioned between EtOAc and water. The organic layer was washed with brine, dried over MgSO4, diluted with hexane, and filtered through silica gel pad (eluted with 50% EtOAc in hexane). The filtrate was concentrated at reduced pressure to give crude di-tert-butyl [6′-(3,6-dihydro-2H-pyran-4-yl)dispiro[1,3-oxazole-4,4′-chromene-3′,3″-oxetan]-2-yl]imidodicarbonate which was used for the next reaction without further purification.

Provenance & Evidence