Ethanol → HCID 21109907, compound

Participants

Reaction Steps

A mixture of 5.5 g (20.2 mmol) of 3-(4-piperidinyl)-5-(phenylmethyl)-imidazolidin-2,4-dione, 4.0 g (20.1 mmol) of 1-(1,1-dimethylethoxycarbonyl)-4-piperidinone, 8 ml (20 mmol) of titanium(IV)-isopropoxide and 100 ml of anhydrous ethanol was stirred for 1 hour at ambient temperature. Then 0.89 g (13.45 mmol) of 95% sodium cyanoborohydride was added, the mixture was adjusted to pH 5 by the dropwise addition of glacial acetic acid and stirred overnight at ambient temperature. The mixture was stirred into 200 ml of water and freed from the precipitate formed. The filtrate was evaporated down in vacuo until no more ethanol passed over, the aqueous phase remaining was made alkaline with sodium hydroxide and extracted exhaustively with dichloromethane. Conventional working up of the extracts yielded 5.0 g (54% of theoretical) of colourless crystals.

Provenance & Evidence