5435. Lenacil

Nomenclature

CAS number: 2164-08-1
3-Cyclohexyl-6,7-dihydro-1H-cyclopentapyrimidine-2,4-(3H,5H)-dione; 3-cyclohexyl-5,6-trimethyleneuracil; 3-cyclohexyl-1,5,6,7-tetrahydro-2H-cyclopentapyrimidine-2,4(3H)-dione; Du Pont 634; Venzar (DuPont).
C13H18N2O2; mol wt 234.29.
C 66.64%, H 7.74%, N 11.96%, O 13.66%.

Description and references

Prepn: S. Senda, H. Fujimura, JP 62 4892 (1962), C.A. 59, 642g (1963); and herbicidal activity: E. J. Soboczenski, US 3235360 (1966 to duPont Nemours). Synthesis: S. Senda et al., Chem. Pharm. Bull. 21, 1894 (1973). Mode of action: C. E. Hoffmann, Pestic. Chem., Proc. 2nd Int. Congr. Pestic. 5, A. S. Tahori, Ed., (Gordon and Breach Science Publishers, New York, 1972) pp 65-85. Field evaluation: J. G. Hilton, W. E. Bray, Proc. 12th Brit. Weed Contr. Conf. 485 (1974). GC determn in soils: D. J. Caverly, R. C. Denney, Analyst 102, 576 (1977). Soil persistence: M. Tena et al., Weed Res. 23, 245 (1982). Field tolerance: D. V. Clay, Tests Agrochem. Cultiv. 11, 80 (1990).

Chemical structure

Properties

Crystals from methanol or dioxane, mp >290° (Senda, Fujimura). Also reported as light grey crystals from DMF, mp 310-313° (Soboczenski). Technical product properties: odorless, white to tan crystalline solid. d20 1.32 kg/l. Vapor pressure (25°): 0.2 μPa. Soly in water 6 mg/l; in xylene: 2 g/l. LD50 (80% wettable powder) orally in rats: >11,000 mg/kg. LC50 96 hr in bluegill sunfish; rainbow trout: 100-1000; 135 mg/l. LC50 8 day in bobwhite quail, Peking duck (mg/kg): 2300, >5620. (DuPont technical data sheet).

Use

Herbicide.