epsilon-CAPROLACTONE → 6-Hydroxycaproamide

Participants

Reaction Steps

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.

Provenance & Evidence