Hydrochloric Acid → N-methyl-N-ethylthio-N'-(3,4-dichlorophenyl)-urea

Participants

Reaction Conditions

Reaction Steps

A solution of 67 g of sulfuryl chloride in 100 ml of methylene chloride was added dropwise to a solution of 61 g of diethyldisulfide in 600 ml of methylene chloride cooled to -40° C. and after the temperature was raised to -5° C., the mixture was stirred for 5 minutes. The mixture was cooled to -40° C. and a solution of 57 g of N-methyl-N'-(3,4-dichlorophenyl)-urea in 460 ml of pyridine was added dropwise thereto. The mixture was stirred at -40° C. for 1 hour and for another hour at -20° C. The mixture was poured into an ice-water mixture and the pH was adjusted to 3.5 by addition of concentrated hydrochloric acid. The organic phase was decanted and the aqueous phase was extracted with methylene chloride. The combined organic phases were washed with water, dried and evaporated to dryness under reduced pressure. The residue was crystallized from isopropyl ether and subjected to chromatography over silica gel. Elution with a 7-3 benzene-ethyl acetate mixture gave 22 g of N-methyl-N-ethylthio-N'-(3,4-dichlorophenyl)-urea melting at 71° C.

Provenance & Evidence