Oxalic Acid → 1[n-[(1,3-Benzodioxol-5-yl)sulfonyl]-n-(2-methylpropyl)amino]-3(s)-[bis(phenylmethyl)amino]-4-phenyl-2(r)-butanol

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Reaction Steps

To a 5000 mL, 3-necked flask fitted with a mechanical stirrer was added N-[3(S)-[N,N-bis(phenylmethyl)amino]-2(R)-hydroxy-4-phenylbutyl]-N-isobutylamine.oxalic acid salt (354.7 g, 0.7 mole) and 1,4-dioxane (2000 mL). A solution of potassium carbonate (241.9 g, 1.75 moles) in water (250 mL) was then added. The resultant heterogeneous mixture was stirred for 2 hours at room temperature followed by the addition of 1,3-benzodioxole-5-sulfonyl chloride (162.2 g, 0.735 mole) dissolved in 1,4-dioxane (250 mL) over 15 minutes. The reaction mixture was stirred at room temperature for 18 hours. Ethyl acetate (1000 mL) and water (500 mL) were charged to the reactor and stirring continued for another 1 hour. The aqueous layer was separated and further extracted with ethyl acetate (200 mL). The combined ethyl acetate layers were washed with 25% brine solution (500 mL) and dried over anhydrous magnesium sulfate. After filtering and washing the magnesium sulfate with ethyl acetate (200 mL), the solvent in the filtrate was removed under reduced pressure yielding the desired sulfonamide as an viscous yellow foamy oil (440.2 g 105% yield). HPLC/MS (electrospray) (m/z 601 [M+H]+].

Provenance & Evidence