Hydrochloric Acid → N-(4-iso-propylbenzenesulfonyl)-alpha-(4-cyano-2-n-propylphenoxy)-3,4-methylenedioxyphenyl-acetamide

Participants

Reaction Steps

To a stirred solution of 2.92 g (8.61 mmol) of the product of Step D in 40 mL of methylene chloride was added 2.31 g (12.05 mmol) of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, 1.26 g (10.33 mmol)of 4-dimethylaminopyridine, and 1.89 g (9.47 mmol) of 4-iso-propylbenzenesulfonamide. The reaction mixture was stirred overnight and after TLC analysis (80:15:1 chloroform/methanol/ammonium hydroxide) was poured into 1N HCl and extracted with ethyl acetate. The extract was washed with brine, dried over magnesium sulfate, filtered, and evaporated in vacuo. The residue was partially purified with silica gel flash chromatography eluting first with 40% ethyl acetate-hexane and then with 3% methanol-methylene chloride to flush the column. All of the product fractions were contaminated and were chromatographed. The 3.86 g of semi-purified material was dissolved in 15 mL of acetonitrile and 15 mL of water and filtered through a 0.45 μM membrane filter. The compound was purified using a Waters Delta Prep 3000 HPLC by applying the filtered solution to an M1000 Prep-Pak module containing a 47×300 mm 15 mM DeltaPak C18 column and eluting at 50 mL/min first using 50% A (95-5 acetonitile-water) and 50% B (95-5 water-acetonitrile) with 0.1% TFA for 15 minutes and then 70% A (95-5 acetonitile-water) and 30% B (95-5 water-acetonitrile) both with 0.1% TFA. The column effluent was monitored simultaneously at 210 and 277 nM with a Waters model 490 UV-visible detector and the purified fractions were combined in a round bottom flask and concentated in vacuo to afford 1.45 g (38%) of the title compound as an amorphous solid.

Provenance & Evidence