m-Chloroperbenzoic acid → HCID 20548869、化合物

100 g (0.38 mol) of 1-(β,β,β-trichloroethoxycarbonyl)-1,2,5,6-tetrahydropyridine are dissolved in 1,200 ml of methylene chloride and the solution is treated with 157 g (0.77 mol) of 85% strength m-chloroperbenzoic acid in portions. The slightly exothermic reaction is kept at room temperature by means of a water bath. After the addition has ended (which takes about 2 hours), the reaction mixture, in which a white suspension forms, is stirred for a further 15 hours at room temperature. The m-chlorobenzoic acid which has precipitated is filtered off and the filtrate is washed with a saturated aqueous solution of sodium carbonate, then with aqueous iron-II sulphate solution, then with 0.1 N sodium hydroxide solution and finally with water, dried over sodium sulphate and evaporated under a water pump vacuum. The oil which remains is dissolved in 100 ml of benzene and the solution is filtered through a layer of silica gel. Elution with a benzene/ethyl acetate mixture (1:1) and evaporation of the solvent gives pure 3,4-epoxy-1-(β,β,β-trichloroethoxycarbonyl)-piperidine in the form of a slightly orange coloured oil.