Iodine → (+,-) Trans Propane-2-sulfonic Acid [2-(4-iodo-phenyl)-cyclopentyl]-amide

Participants

Reaction Conditions

Reaction Steps

(+,−) Trans-propane-2-sulfonic acid (2-phenyl-cyclopentyl)-amide (0.52 g, 1.47 mmol, prepared in example 1) was dissolved in 30 mL of glacial acetic acid. To this solution was added concentrated sulfuric acid (0.16 mL, 1.61 mmol) at room temperature followed by iodine (0.19 g, 0.74 mmol), and diiodine pentoxide (0.20 g, 0.59 mmol). The reaction was then protected from light and heated to 90° C. and stirred for 22 hours. To the dark brown reaction mixture was slowly added 10% aqueous sodium bisulfite. The mixture was cooled to 0° C. for 1 hour and a light brown solid collected by filtration. The solid was dissolved in warm diethyl ether and washed with water (2×), then saturated sodium bicarbonate (1×). The organic layer was separated, dried (Na2SO4), filtered and concentrated in vacuo to give 435 mg (75%) of the title compound. The NMR was consistent with the assigned structure.

Provenance & Evidence