Hydrochloric Acid → HCID 21506798, compound

Participants

Reaction Steps

To 24.3 grams (0.1 M) of 2,3-dihydrospiro-[naphthalene-1(4H),3'-piperidine]-2',4,6'-trione in 300 milliliters of dry dimethylformamide maintained under nitrogen atmosphere was added with stirring 4.37 grams (0.1 M) of a 55 per cent suspension of sodium hydride in mineral oil. After stirring for five minutes, 16.0 grams (0.1 M) of diethyl sulfate were added in one portion. The slightly exothermic reaction mixture was allowed to stir for a short time and concentrated hydrochloric acid was added dropwise until the reaction mixture was slightly acidic. The reaction solvent was removed under reduced pressure at steam bath temperature and the resulting oil extracted into ether. The ether extracts were washed with 5 percent sodium hydroxide solution, water, and then dried (MgSO4). After filtration, the ether was removed, leaving a residue, which was recrystallized from diethyl ether to give 34.9 grams (64%) of 1'-ethyl-2,3-dihydrospiro-[naphthalene-1(4H),3'-piperidine]-2',4,6'-trione, melting point 85.5°-89° C.

Provenance & Evidence