1-Methyl-1,4-cyclohexadiene → (R)-5-(2-Amino-1-hydroxyethyl)-8-hydroxyquinolin-2(1H)-one hydrochloride

Participants

Reaction Conditions

Reaction Steps

To a solution of (R)-5-(2-azido-1-((tert-butyldimethylsilyl)oxy)ethyl)-8-(benzyloxy)quinolin-2(1H)-one (4.50 g, 10.0 mmol) in ethanol (50 mL) was added 10% palladium on charcoal (4.50 g) followed by 1-methyl-1,4-cyclohexadiene (11.0 mL, 97.9 mmol). The reaction was warmed to 60° C. (CARE—POSSIBLE EXOTHERM) and then stirred at 60° C. for 2 hours. The reaction mixture was allowed to cool and filtered through a pad of celite. The filter cake was washed with further ethanol and the filtrate was evaporated at reduced pressure. The residue was evaporated from iso-propanol (×2) and dissolved in iso-propanol (30 mL). HCl-dioxane (4 M, 50 mL, 200 mmol) was added and the reaction mixture stirred at RT for 18 hours. The resultant suspension was filtered, the filter cake washed with ether and the solid dried under vacuum in the presence of P2O5 to afford the title compound (1.65 g, 62%).

Provenance & Evidence