Dimethylformamide → N-(Benzylsulfonyl)-7-(2,3-di-p-tolyl-7,8-dihydropyrido[2,3-b]pyrazin-5(6H)-yl)heptanamide

Participants

Reaction Steps

A mixture comprising 7-(2,3-di-p-tolyl-7,8-dihydropyrido[2,3-b]pyrazin-5(6H)-yl)heptanoic acid [prepared according to the preparation procedures disclosed in PCT patent application PCT/EP2011/062028, Example 4.3] (100 mg, 0.225 mmol) in dry DCM (5 ml) at RT, under nitrogen, was treated with DMF (1.746 μl, 0.023 mmol) followed by oxalyl chloride (0.022 ml, 0.248 mmol). After stirring at RT for 2 hours, DIPEA (0.157 ml, 0.902 mmol) was added followed by phenylmethane sulfonamide (154 mg, 0.902 mmol). The resulting mixture was stirred at RT for 2 hours and subsequently added to water (30 ml). The mixture was extracted with DCM (×3) and the combined organic extracts were passed through a phase separating column. The organic solvent was removed under reduced pressure and purification of the crude residue by chromatography on silica eluting with 0-40% EtOAc in iso-hexane afforded an orange solid. The solid was dissolved in a minimal volume of EtOAc and treated with an excess of iso-hexane. The resulting suspension was filtered and the solid rinsed with iso-hexane (×3) the afford the titled compound;

Provenance & Evidence