1,4-Dioxane → 1H-Indole-3-carboxylic acid, 1-[1-[1-[(1,1-dimethylethoxy)carbonyl]-4-piperidinyl]ethyl]-2-methyl-, methyl ester

Participants

Reaction Conditions

Reaction Steps

A 250 mL round bottom flask was charged with a magnetic stir bar, (R or S,Z)-tert-butyl 4-(1-(3-(2-bromophenyl)-4-methoxy-4-oxobut-2-en-2-ylamino)ethyl)piperidine-1-carboxylate (3.33 g, 6.92 mmol), RuPhos Pre-catalyst II (Chloro-(2-Dicyclohexylphosphino-2′,6′-diisopropoxy-1,1′-biphenyl)[2-(2-aminoethyl)phenyl]palladium(II)-methyl-t-butyl ether adduct) (0.463 g, 0.553 mmol), dicyclohexyl(2′,6′-diisopropoxybiphenyl-2-yl)phosphine (0.387 g, 0.830 mmol), anhydrous 1,4-dioxane (27.7 ml, 6.92 mmol), and sodium methoxide (0.561 g, 10.38 mmol). The reaction mixture was purged and back-filled with nitrogen and heated to 100° C. with stirring overnight before being allowed to cool to rt. The reaction was diluted with ethyl acetate (˜100 ml) and the mixture was filtered through a bed of diatomaceous earth. The filtrate was pre-absorbed onto silica gel (˜30 g) and purified via silica gel chromatography (120 g) using ethyl acetate/hexanes (1:1) as eluent to afford the title compound (2.01 g, 4.77 mmol, 68.9% yield).

Provenance & Evidence