4-Toluenesulfonyl chloride → 3-(benzyloxy)-10,11-dihydro-8H-[1,4]oxazino[4',3':1,2]imidazo[4,5-c]quinolin-6-amine

Participants

Reaction Steps

A 1-liter round bottom flask was charged with 3-(benzyloxy)-10,11-dihydro-8H-[1,4]oxazino[4′,3′:1,2]imidazo[4,5-c]quinoline (5.0 g, 15.1 millimoles (mmol)) and dichloromethane (200 mL). To this solution was slowly added in small portions 3-chloroperoxybenzoic acid (mCPBA) (5.2 g of 50% pure material, 15.1 mmol, 1.0 eq). The reaction was maintained at room temperature for 3 hours. Concentrated ammonium hydroxide (100 mL) was added followed by p-toluenesulfonyl chloride (3.2 g, 16.6 mmol, 1.1 eq) in small portions. The reaction was maintained at room temperature overnight. The reaction was quenched with water (200 mL) and stirred for an additional hour. The aqueous layer was separated and extracted with dichloromethane (3×50 mL). The combined organic fractions were concentrated to provide 3-(benzyloxy)-10,11-dihydro-8H-[1,4]oxazino[4′,3′:1,2]imidazo[4,5-c]quinolin-6-amine as an off-white solid. A small amount of product was recrystallized from acetonitrile and carried on to the next step.

Provenance & Evidence