Acetic Acid → HCID 19844125, compound

Participants

Reaction Steps

A solution of the product of stage (i) (5.08 g) in glacial acetic acid (40 ml) containing boron trifluride, etherate (6.7 ml) was heated on a steam bath for 15 min, cooled, diluted with water (200 ml) basified (Na2CO3) and extracted with ethyl acetate (2×200 ml). The combined organic extracts were dried (MgSO4) and evaporated in vacuo to give crude 3-[2-(1,3-dihydro-1,3-dioxo-2H-isoindol-2-yl)ethyl]-N-phenyl-1H-indole-5-sulphonamide as a foam (4.8 g). The foam was suspended in ethanol (100 ml) containing hydrazine hydrate (5 ml), heated at reflux for 2 h, cooled, the ethanol removed in vacuo and the residue partitioned between sodium carbonate (2 N, 150 ml) and ethyl acetate (2×150 ml). The combined organic extracts were dried (Na2SO4) and evaporated in vacuo to give a foam which was purified by flash chromatography eluted with dichloromethane:ethanol:ammonium hydroxide (20:5:0.2) to give the title compound free base (0.57 g) as a solid. The free base was dissolved in a solution of maleic acid (0.21 g) in methanol (10 ml), and the salt precipitated by the addiion of ethyl acetate (100 ml) and dry ether (300 ml). The salt was filtered off and dried in vacuo to give the title compound as a solid. (0.55 g) m.p. 145°-147°.

Provenance & Evidence