Urea → HCID 10025688, compound

Participants

Reaction Steps

A mixture of the diastereoisomers of (4-aminomethyl-1-phenylcyclohexyl)dimethylamine (466 mg, 2.0 mmol.) was added to a solution of (3-phenylpropyl)carbamic acid phenyl ester (511 mg, 2.0 mmol.) in dioxane (15 ml), and heating was carried out for 12 h at reflux. For working up, the mixture was concentrated, water (10 ml) was added to the residue, the pH was adjusted to 11 with 5M NaOH, and extraction was carried out with EE (3×20 ml). The combined extracts were washed with 1M NaOH (1×5 ml), dried, filtered and concentrated. The residue was a diastereoisomeric mixture of the target products, which was separated by flash chromatography on silica gel (60 g) and purified (eluant: 1000 ml of ethanol/EE 1:1). The non-polar urea (310 mg, 0.79 mmol., yellow oil) was dissolved in acetone (5 ml) and 2-butanone (15 ml), and chlorotrimethylsilane (150 μl, 1.2 mmol.) was added dropwise at RT, with stirring. After stirring for 1 h, the reaction solution was reduced to about 1 ml in vacuo, ether (10 ml) was added thereto, and vigorous stirring was carried out for 1 h at RT. The solid that formed was filtered off with suction, washed with ether (3×3 ml) and dried in vacuo. 339 mg of the hydrochloride of the non-polar diastereoisomer of 1-(4-dimethylamino-4-phenylcyclohexylmethyl)-3-(3-phenylpropyl)urea were obtained (white solid, m.p. 85–95° C.).

Provenance & Evidence