Triphenylphosphine → 4-[2-(1,1-Dioxo-1lambda6-thiomorpholine-4-carbonyl)-1-isopropyl-1H-indol-5-yloxy]-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a cold (0° C.) mixture of (1,1-dioxo-1λ6-thiomorpholin-4-yl)-(5-hydroxy-1-isopropyl-1H-indol-2-yl)-methanone (890 mg, 1.0 eq.), 1-tert-butyloxycarbonyl-4-hydroxy-piperidine (659 mg, 1.2 eq.) and triphenylphosphine (858 mg, 1.2 eq.) in tetrahydrofuran (6 mL) was added dropwise a solution of di-tert-butyl-azodicarboxylate (746 mg, 1.0 eq.) in tetrahydrofuran (4 mL). The reaction mixture was stirred for 15 h at room temperature, concentrated in vacuo, then purified on silica eluting with a gradient of cyclohexane/ethyl acetate. One fraction was isolated to yield 434 mg (31.6%) of the desired product as white oil. MS (m/e): 520.7 (MH+, 100%).

Provenance & Evidence