3-Chloro-2-chloromethyl-1-propene → tert-Butyl 6-methylidene-1,4-oxazepane-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

Sodium hydride (992.6 mg, 60% in mineral oil, 24.8 mmol) was added portionwise to a solution of (2-hydroxy-ethyl)-carbamic acid tert-butyl ester (2 g, 12.4 mmol) in 1-methyl-2-pyrrolidinone (20 ml) at −2° C., in order to maintain the temperature below 5° C. The mixture was then stirred for 30 minutes, cooled to −5° C., and a solution of 3-chloro-2-chloromethyl-1-propene (1.44 ml, 12.4 mmol) in 1-methyl-2-pyrrolidinone (10 ml) added dropwise in order to maintain the temperature below 3° C. Once addition was complete, the reaction mixture was allowed to warm to room temperature and stirred for a further 18 hours. The reaction mixture was diluted with water and extracted with ether (2×50 ml). The combined organic extracts were dried over magnesium sulphate and evaporated under reduced pressure. The residual oil was purified by column chromatography on silica gel using ethyl acetate:pentane (10:90) to give the title compound as a clear oil, 713 mg.

Provenance & Evidence