Noruron

Noruron (or norea) is a premërgent urea herbicide active ingredient. It is considered obsolete, but may still be used. Introduced in the US in 1962, was used to control grass weeds and broadleaf weeds on crops including broomcorn, cotton, potatoes, sugarcane, spinach, soybeans and sorghum.^[1][4]

Noruron

Names
Preferred IUPAC name rac-N,N-dimethyl-N'-[(3aR,4S,5R,7S,7aR)-octahydro-1H-4,7-methanoinden-5-yl]urea
Other names Norea 1,1-dimethyl-3-[(1S,2R,6R,7S,8R)-8-tricyclo[5.2.1.02,6]decanyl]urea N,N-Dimethyl-N′-(octahydro-4,7-methano-1H-inden-5-yl)urea l-5-(3a,4,5,6,7,7ahexahydro-4, 7 -methanoindanyl-3 ,3-dimethylurea
Identifiers
CAS Number	18530-56-8
3D model (JSmol)	Interactive image
ChemSpider	32697651
ECHA InfoCard	100.038.536
EC Number	242-406-2
PubChem CID	12313523
UNII	4Z7VLM178S
CompTox Dashboard (EPA)	DTXSID6040292
InChI InChI=1S/C13H22N2O/c1-15(2)13(16)14-12-7-8-6-11(12)10-5-3-4-9(8)10/h8-12H,3-7H2,1-2H3,(H,14,16) Key: YGLMVCVJLXREAK-UHFFFAOYSA-N
SMILES O=C(NC1CC2CC1C3CCCC23)N(C)C
Properties
Chemical formula	C13H22N2O
Molar mass	222.332 g·mol−1
Density	1100 kg/m3[1]
Melting point	177 °C (351 °F; 450 K)[2]
Solubility in water	194 mg/L[1]
Hazards
GHS labelling:[3]
Pictograms
Signal word	Warning
Hazard statements	H302, H311
Precautionary statements	P264, P280, P312, P321, P361+P364, P501
Lethal dose or concentration (LD, LC):
LD50 (median dose)	2000 mg/kg (rat, oral) 723 mg/kg (rabbit, dermal)[3]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Legal Status

Noruron is not approved for use in the EU.^[5]

Chemistry

Noruron is stereochemically racemic, with 5 stereocenters.^[6] It is a chiral molecule, and the technical grade stuff is mixed from two racemates.^[7]

Application

Noruron is applied at 0.75 to 4 kg/ha of active ingredient, typically supplied as wettable powder or granules.^[4]

Performance

Norea (in conifer seedbeds in Connecticut) provided fair to excellent weed control for two months, at 1.5 to 2 lbs/ac (1.68 to 2.24 kg/Ha), with injury to pine and spruce seedlings in most tests, though at 4 lbs/ac it injured white pine. Norea's control was comparable to simazine but shorter-lasting.^[8]

A 1960s trial found noruron promising for growing dioscorea crops (such as yams), as of the tested herbicides it showed the most control without causing crop-injury.^[9]

Products

It has been sold under the tradename "Herban",^[1] a 76% norea wettable powder.^[10] "Daban-1", "Maban-2" were liquid formulations containing 1 lb per gallon Herban. Maban was registered in 1967 and discontinued in 1989.^[11][12] Herban was trademarked in 1963, renewed in 1983, but expired in 2004.^[13]

Maban was registered for use on cotton, drainage ditch banks, fencerows, noncrop areas, rights-of-way, and storage yards.^[12]