反应详情

A solution of 27 g of N-methyl-N-(2-thiapropyl)-N'-(3,4-dichlorophenyl)-urea in 250 ml of methylene chloride was added at 10° C. to a solution of 34.5 g of m-chloroperbenzoic acid in 520 ml of methylene chloride and the mixture was stirred at room temperature for 3 1/2 hours. The precipitate was filtered off and the filtrate was distilled to dryness under reduced pressure. The residue was dissolved in ethyl acetate and the m-chlorobenzoic acid formed was removed by filtration. The organic filtrate was washed with aqueous 5% sodium bicarbonate solution, then with water, dried and concentrated to dryness under reduced pressure. The residue was subjected to chromatography over silica gel and was eluted with ethyl acetate and crystallized from isopropyl ether to obtain 11 g of N-methyl-N-(methylsulfonylmethyl)-N'-(3,4-dichlorophenyl)-urea melting at 159° C. A microanalytical sample was obtained by crystallization from ethyl acetate.

1. filtrationThe precipitate was filtered off
2. distillationthe filtrate was distilled to dryness under reduced pressure
3. dissolutionThe residue was dissolved in ethyl acetate