Sodium borohydride → N-{4-[(1R)-1-aminopropyl]-2-ethylphenyl}methanesulfonamide

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of N-(2-ethyl-4-propionylphenyl)methanesulfonamide (7.8 mmol) in tetrahydrofuran (15 ml) and titanium (IV) ethoxide (15 ml), (R)-(+)-2-methyl-2-propanesulfinamide (7.8 mmol) was added. The mixure was stirred at 80° C. for 16 hours. Upon completion, as determined by LC-MS, the mixture was cooled to room temperature and then to 0° C. before it was added dropwise into a 0° C. solution of sodium borohydride (1.18 g, 31 mmol) in tetrahydrofuran (15 ml). The mixture was stirred at 0° C. for 3 hours and then quenched with methanol. After stirring at room temperature for 2 hours, Celite pad and water were added to the mixture, filtered thorough Celite, and washed with dichloromethane-ethyl acetate-methanol. The filtration was evaporated under the reduced pressure and the given residue was purified by silica gel eluting with dichloromethane-ethyl acetate (1:1) to afford the title compound as yellow oil. It was dissolved in methanol (30 ml) and hydrogen chloride-methanol (30 ml) was added. The solution was stirred at room temperature for 1 hour. After the solvent was removed under the reduced pressure, the product was recrystalized from diethylether-methanol to afford the desired product as hydrogen chloride salt.

Provenance & Evidence