1-Chloroethyl chloroformate → 2-(S)-(3,5-Dichlorobenzyloxy)-3-(S)-phenylmorpholine

Participants

Reaction Conditions

Reaction Steps

A solution of 0.33 g (0.77 mmole) of 4-benzyl-2-(S)-(3,5-dichlorobenzyloxy)-3-(S)-phenylmorpholine (from Example 44, Step B) and 0.22 g (1.54 mmole) of 1-chloroethyl chloroformate in 4.5 mL of 1,2-dichloroethane was placed in a pressure vial which was lowered into an oil bath which was heated to 110° C. After stirring for 60 hr the solution was cooled and concentrated in vacuo. The residue was dissolved in 7 mL of methanol and the resulting solution was heated at reflux for 30 min. The mixture was cooled and treated with several drops of concentrated aqueous ammonia and the solution was concentrated. The residue was partly purified by flash chromatography on 67 g of silica eluting with 1.5 L of 100:1 methylene chloride: methanol, and the rich cuts were purified by flash chormatography on 32 g of silica eluting with 50:50 hexanes: ethyl acetate and then 50:50:5 hexanes:ethyl acetate:methanol to give 0.051 g (20%) of an oil, which by 1H NMR was pure cis morpholine.

Provenance & Evidence