Sodium hydride → HCID 20306016, compound

Participants

Reaction Steps

N-Acetyl-4-hydroxypiperidine (57.2 g.) in dry D.M.F. (250 ml.) was added dropwise to a stirred suspension of sodium hydride (23.2 g., 50% dispersion in mineral oil) in dry D.M.F. (200 ml.) under an atmosphere of nitrogen and with external cooling in an ice/water bath. The suspension was allowed to warm to room temperature then stirred for 5 hours. Bromoacetaldehyde diethylacetal (94.7 g.) was added slowly to the stirred reaction mixture with cooling then the mixture was stirred at room temperature for 18 hours. A further quantity of sodium hydride (23.2 g.) was added portionwise and stirring continued until effervescence had ceased. A further 100 ml. dry D.M.F. was added and the mixture cooled in an ice/water bath while a second batch of bromoacetaldehyde diethylacetal (94.7 g.) was slowly added. The mixture was stirred at room temperature for 3 hours then isopropopanol (150 ml.) added to destroy excess sodium hydride. The suspension was filtered, the filtrate concentrated under reduced pressure then the residue taken up in water and extracted with chloroform. The chloroform extract was dried (Na2SO4), the solvent evaporated in vacuo and the residue distilled to give N-acetyl-4-(2,2-diethoxyethoxy)piperidine (61.5 g.), b.p. 142°-145° C./3 mm., characterized by n.m.r.

Provenance & Evidence