Toluene → Methyl 4-(5-cyano-7-isopropenyl-1,3-benzoxazol-2-yl)benzoate

Participants

Reaction Conditions

Reaction Steps

To a 5-L, 3-neck round-bottom flask fitted with a stirring paddle, a condenser blanketed with nitrogen, and a thermocouple, was added 4-(7-bromo-5-cyano-1,3-benzoxazol-2-yl)benzoate (55.5 g, INTERMEDIATE 1) toluene (2 L), water (375 ml), ethanol (150 ml), 2M aqueous sodium carbonate (250 ml), and isopropenylboronic acid (83.4 g, INTERMEDIATE 3). The mixture was purged with nitrogen three times and then tetrakis(triphenylphosphine)palladium(0) (9.1 g) was added, and the mixture was purged three times with nitrogen. The mixture was heated to reflux (91° C.) and stirred at this temperature overnight. The mixture was then cooled to 20° C. and the product was filtered, washed with water, dried, and transferred to a 3-L round-bottom flask and rinsed with toluene (1 L). Residual solvent was removed in vacuo. Mass spectrum (ESI) 319.1 (M+1).

Provenance & Evidence