Methyl Ethyl Ketone → HCID 70203632, compound

Participants

Reaction Steps

A mixture of the above methanesulfonate (2.5 g), (R)-3-piperidinecarboxylic acid ethyl ester tartrate (4.6 g, 15.1 mmol), dry potassium carbonate (6,3 g, 45.4 mmol), and methyl ethyl ketone (100 ml) was heated at reflux temperature for 48 hours under an atmosphere of nitrogen. The cooled reaction mixture was quenched with water (100 ml) and extracted with diethyl ether (100 ml). The organic extract was washed with saturated brine (80 ml), dried (Na2SO4), filtered and the solvent evaporated in vacuo. The crude product (3.1 g) was purified by column chromatography on silica gel (600 ml) using a mixture of ethyl acetate/heptane (1:2) as eluent. This afforded 1.9 g of crude (R)-1-(3-(11,12-dihydro-dibenz[a,e]cycloocten-5-yl)-1-propyl)-3-piperidinecarboxylic acid ethyl ester. The ethyl ester was suspended in water (150 ml) and concentrated hydrochloric acid was added to pH=1. The aqueous phase was washed with diethyl ether (100 ml) basified to pH=8 with 20% sodium hydroxide and extracted with diethyl ether (2×100 ml). The combined organic extracts were washed with brine (80 ml), dried (MgSO4), filtered and the solvent was evaporated in vacuo affording 1.1 g (36%) of (R)-1-(3-(11,12-dihydro-dibenz[a,e]cycloocten-5-yl)-1-propyl)-3-piperidinecarboxylic acid ethyl ester as an oil.

Provenance & Evidence