Buturon

Buturon is a methylurea, phenylurea herbicide,^[4] used to control grassy weeds, largely on cereals. It is now considered obsolete,^[1] having been first released as "Eptapur" in 1962.^[5]

Buturon

Names
Preferred IUPAC name 1-but-3-yn-2-yl-3-(4-chlorophenyl)-1-methylurea
Identifiers
CAS Number	3766-60-7
3D model (JSmol)	Interactive image
ChEBI	CHEBI:82199
ChEMBL	ChEMBL3185882
ChemSpider	18451
ECHA InfoCard	100.021.080
KEGG	C19074
PubChem CID	19587
UNII	1961BJU91F
CompTox Dashboard (EPA)	DTXSID5041699
InChI InChI=1S/C12H13ClN2O/c1-4-9(2)15(3)12(16)14-11-7-5-10(13)6-8-11/h1,5-9H,2-3H3,(H,14,16) Key: BYYMILHAKOURNM-UHFFFAOYSA-N
SMILES CC(C#C)N(C)C(=O)NC1=CC=C(C=C1)Cl
Properties
Chemical formula	C12H13ClN2O
Molar mass	236.70 g·mol−1
Appearance	Colourless crystalline solid[1]
Density	1.233[2]
Melting point	145 °C (293 °F; 418 K)[1]
Solubility in water	30 mg/L[1]
Solubility in acetone	279 g/L[1]
Solubility in methanol	128 g/L[1]
Solubility in benzene	9.8 g/L[1]
Vapor pressure	0.01 mPa[1]
Hazards
GHS labelling:
Pictograms	[2]
Signal word	Danger
Hazard statements	H302, H311[1]
Precautionary statements	P262, P264, P270, P280, P301+P317, P302+P352, P316, P321, P330, P361+P364, P405, P501
Flash point	>100°C[2]
Lethal dose or concentration (LD, LC):
LD50 (median dose)	>1791 mg/kg (rat, oral) 500 mg/kg (rabbit, dermal)[1][3]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Buturon's HRAC classification is Group C (Australia), Group C2 (global) or Group 5 (numeric).^[1]

Rats metabolise buturon within 4 days and remove 68% and 20% by urine and faeces respectively.^[6]

Soil behaviour

Buturon rapidly degrades in the environment, and is not persistent, though some metabolites are.^[5]

Wheat metabolises about 25% of buturon after seven days. Nutrient deficient plants metabolise it significantly faster though. The main metabolite groups are carbamates, unstable products, a group containing p-chloroacetanilide and conjugates. Nutrient-deficiency also decreases absorption and translocation, which is conjectured to passively rely on the flow of water. Plant metabolism may occur independently in roots and shoots.^[7]

Buturon has low volatility.^[1]

Safety

In a trial on mice given high daily doses of buturon, 100 to 400 mg/kg/day, and for comparison the LD₅₀ is 1791 mg/kg, buturon induced postimplantative loss and retardation of development at doses over 300 mg/kg/day, and a dose-dependent trend of cleft palate, wavy or fused ribs and hypoplasia of the upper jaw.^[8]

Usage

Buturon is usually sold as a wettable powder, to be applied on berry fruits, maize, vines, and cereals including wheat and barley, to control such weeds as spurge, annual meadow grass and foxtails.^[1]

It has been sold under the tradenames "Arisan", "Basfitox" and "Eptapur".^[1]