Ethanol → HCID 70184421, compound

Participants

Reaction Conditions

Reaction Steps

469.2 g (1.3 mol) of ethyl 3-(2-ethoxycarbonylethyl)amino-4-(3-methoxyphenyl)-2-dimethylbutanoate (5) [R2 =m-CH3O] are dissolved in 7.8 liters of toluene and first about 100 ml of a solvent/water mixture are distilled off. The residue is allowed to cool to about 70° C., mixed with 158.3 g (1.4 mol) of potassium tert.-butoxide and heated to 105° C. for 40 minutes, whilst the ethanol formed is distilled off. It is then cooled to 5 C and mixed with 1.2 liters of ice water and 280 ml of conc. hydrochloric acid. 1.2 liters of ether and 220 ml of conc. ammonia solution are added, the organic phase is separated off and the aqueous phase is extracted twice more with 600 ml of diethylether. The combined organic phases are washed twice with 600 ml of water, dried over sodium sulphate and evaporated down in vacuo. The 5-carbethoxy-3,3-dimethyl-2-(3-methoxyphenyl)-methyl-4-piperidone (6) is isolated in a yield of 390.1 g (95.1% of theory) as a reddish-brown oil.

Provenance & Evidence