反应详情

ε-Caprolactone was charged to a flask equipped with a mechanical stirrer and thermometer and cooled in an ice bath to below 5° C. A pre-cooled 30% solution of ammonium hydroxide was added and the reaction temperature was maintained below 5° C. until all ε-caprolactone was consumed as indicated by gas chromatography. The water and excess ammonia were vacuum stripped at 50° C. at the completion of which the acid value was measured to be 2300. The acid by-product was removed via flocculation by addition of lithium hydroxide hydrate in methanol solution and ethyl acetate followed by isopropanol until clarified. A second portion of ethyl acetate was added and the flocculated acid was filtered. All solvents were stripped under reduced pressure at 50° C. to yield 6-hydroxycaproamide (2750 g) as a pale yellow oil which crystallized upon standing at room temperature. Gas chromatographic and NMR spectral data indicated greater than 95% purity.

1. customequipped with a mechanical stirrer
2. temperaturethermometer and cooled in an ice bath to below 5° C
3. customwas consumed
4. customstripped at 50° C. at the completion of which
5. customThe acid by-product was removed via flocculation by addition of lithium hydroxide hydrate in methanol solution and ethyl acetate
6. additionA second portion of ethyl acetate was added
7. filtrationthe flocculated acid was filtered
8. customwere stripped under reduced pressure at 50° C.