Potassium tert-butoxide → 9-Benzyl-1-oxa-4,9-diazaspiro[5.5]undecan-3-one

関与物質

反応手順

To a mixture of compound 398 (41.9 g, 141 mmol) in tetrahydrofuran (300 mL) was added potassium tert-butoxide (31.8 g, 283 mmol), portionwise over 40 minutes. After 3.5 hours of stirring at room temperature, the reaction was concentrated in vacuo. The residue was diluted with DCM and water, and then neutralized with 3N HCl. The remaining solids were filtered off and the filtrate was concentrated to an oil. The residue was taken up in hot ethanol (100 mL). After allowing the solution to cool to ˜45° C., the salts were filtered off, and the filtrate was concentrated to a brown solid. The crude material was purified by flash chromatography (0-20% methanol in DCM with 1% NH4OH) to give compound 399 as an orange solid (22.8 g, 62%). LCMS-ESI (POS), M/Z, M+1: Found 261.1, Calculated 261.1.

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