temperature the solvent was removed in a rotary evaporator and the residue was treated with methylene chloride 100 ml and saturated nahco 3 100 ml and transferred to a reparatory funnel the organic layer was washed with brine 100 ml dried na 2 so 4 filtered and concentrated in vacuo the solid residue was treated with ethyl ether filtered and dried yielding 0 98 g of a dark orange solid 76 a solution of seo 2 0 98 g 8 8 mmol in a mixture of dioxane 50 ml and water 2 ml was heated to reflux in a two neck 250 ml round bottomed flask a solution of 2 methyl 4 propylsulfanyl 1 10 phenanthroline 0 95 g 3 5 mmol in hot dioxane 50 ml was added through an addition funnel over a period of 30 minutes and the reaction mixture was refluxed for additional 1 hour the reaction mixture was filtered while hot and the residue rinsed with more hot dioxane 20 ml and filtered the filtrates were combined and evaporated in vacuo and the residue was treated with methylene chloride 100 ml and a 10 k 2 co 3 aqueous solution 100 ml the aqueous layer was extracted several times with methylene chloride 3 u00d7 100 ml and the combined organic layers were washed with brine dried na 2 so 4 filtered and concentrated the crude product was purified by flash chromatography neutral al 2 o 3 meoh dcm 1 50 to 1 15 to afford the pure product as a brown solid 0 27 g 27 the final step to obtain the compound 5 is carried out in the.