6261. Monuron
Nomenclature
CAS number: 150-68-5
N′-(4-Chlorophenyl)-N,N-dimethylurea; 1,1-dimethyl-3-(p-chlorophenyl)urea; CMU; Karmex Monuron Herbicide; Telvar (DuPont). C9H11ClN2O; mol wt 198.65.
C 54.42%, H 5.58%, Cl 17.85%, N 14.10%, O 8.05%.
Description and references
Prepd by reacting p-chlorophenyl isocyanate with dimethylamine: Bucha, Todd, Science 114, 493 (1951); see also US 2655444; US 2655445; US 2655446; US 2655447. Toxicity study: G. W. Bailey, J. L. White, Residue Rev. 10, 97 (1965). Review: McCall, Agric. Chem. 7, 40 (1952).
Properties
Thin rectangular prisms from methanol, mp 170.5-171.5° (the commercial product melts at 176-177°). Vapor pressure at 25°: 5 × 10-7 mm; at 100°: 178 × 10-5 mm. Slight odor. Stable toward oxygen and moisture under ordinary conditions at neutral pH; elevated temps and more acid or alkaline conditions appreciably raise rate of hydrolysis. Very slightly sol in water and in no. 3 Diesel oil: About 230 ppm at 25°. pH of satd aq soln 6.26. Moderately sol in methanol, ethanol, acetone. Practically insol in hydrocarbon solvents. LD50 orally in rats: 3700 mg/kg (Bailey, White).Derivative
Trichloroacetate.Nomenclature
Monuron TCA; Urox (Allied).C9H11ClN2O.C2HCl3O2; mol wt 362.04.
C 36.49%, H 3.34%, Cl 39.17%, N 7.74%, O 13.26%.
Description and references
Prepn: Gilbert et al., US 2782112 (1957 to Allied Chem.). Effective in control of both weeds and grasses.