反应详情

温度

0 °C

A cooled (0° C.) solution of Boc-isonipecotic acid (5.97 g, 26.0 mmol) and Meldrum's acid (3.75 g, 26.0 mmol) in DMF (54 mL) was treated dropwise with diethyl cyanophosphonate (4.34 mL, 28.6 mmol) and triethylamine (11.2 mL, 80.7 mmol). After stirring at 0° C. for an additional 30 min the reaction mixture was permitted to warm to rt and stir over 3 days. The reaction mixture was concentrated under reduced pressure and ether and 1N HCl solution were added. The aqueous layer was extracted again with ether and the ethereal layers were combined and washed with 1N HCl solution, twice with water, and lastly with brine. He ethereal layer was then dried over anhydrous MgSO4, filtered, and concentrated to give tert-butyl 4-[(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-ylidene)(hydroxy)methyl]piperidine-1-carboxylate which contained approximately 10% of Boc-isonipecotic acid.

1. temperatureto warm to rt
2. stirringstir over 3 days
3. concentrationThe reaction mixture was concentrated under reduced pressure and ether and 1N HCl solution
4. additionwere added
5. extractionThe aqueous layer was extracted again with ether
6. washwashed with 1N HCl solution, twice with water
7. dry with materialwas then dried over anhydrous MgSO4
8. filtrationfiltered
9. concentrationconcentrated