Methyl vinyl sulfone → tert-butyl 4-{[2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl]methyl}-4-[2-(methylsulfonyl)ethoxy]piperidine-1-carboxylate

Participants

Reaction Steps

To a solution of tert-butyl 4-{[2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl]methyl}-4-hydroxypiperidine-1-carboxylate (prepared as described in Part E of Example 4, 1.9 g, 4.3 mmol) in tetrahydrofuran (17 mL) at rt was added solid NaH (60%, 17 mg, 0.43 mmol). After 10 min, methyl vinyl sulfone (0.92 g, 8.6 mmol) was added dropwise. After 1 h, the reaction was quenched with water (50 mL) and extracted with ethyl acetate (50 mL). The organic layer was concentrated under reduced pressure to afford a yellow oil. Purification by flash chromatography (silica gel, eluted with 5% methanol/dichloromethane) yielded tert-butyl 4-{[2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl]methyl}-4-[2-(methylsulfonyl)ethoxy]piperidine-1-carboxylate (0.40 g, 19%).

Provenance & Evidence