Bromacil is a wide spectrum herbicide from the group of uracils . Bromacil was first registered as a pesticide in the United States in 1961 [3] . It is used to control the growth of shrubs in non-cultivated areas [4] . The mechanism of action is based on the inhibition of photosynthesis . It enters the plant through the roots [5] . It is used for non-selective weed and bush control on non-arable lands, as well as for selective weed control in a limited number of crops, such as citrus fruits and pineapple [4] . It was also found that bromacil is well suited to inhibit the growth of perennial herbs.
| Bromacil | |
|---|---|
| General | |
| Systematic name | 5-bromo-3-butan-2-yl-6-methyl-1H-pyrimidin-2,4-dione |
| Traditional names | Bromazil, Borea, Bromax 4G, Cynogan, Uragan, 5-bromo-6-methyl-3- (1-methylpropyl) uracil |
| Chem. formula | C 9 H 13 BrN 2 O 2 |
| Physical properties | |
| condition | solid substance without color and odor [1] |
| Molar mass | 261.12 g / mol |
| Density | 1.55 g / cm³ |
| Thermal properties | |
| T. melt. | 157.5–160 ° C |
| T. sub. | 158.3 ° C |
| Steam pressure | |
| Chemical properties | |
| pK a | 9.30 |
| Solubility in water | very slightly soluble in water (815 mg · l −1 ) [1] |
| Classification | |
| Reg. CAS number | |
| PubChem | |
| Reg. EINECS number | |
| Smiles | |
| Inchi | |
| RTECS | |
| Chebi | |
| ChemSpider | |
| Security | |
| LD 50 | 641 mg · kg −1 ( rat , oral) [1]
|
| R phrases | R22 , R36 / 37/38 , R50 |
| S-phrases | S26 , S61 |
| H phrases | H302 , H315 , H319 , H335 , H400 |
| P-phrases | P261 , P273 , P305 + 351 + 338 |
| GHS icons |   |
Content
- 1 Receiving
- 2 Properties
- 3 Security
- 4 Toxicology
- 5 Use
- 6 notes
Getting
Bromacil can be obtained by reacting isopropylisocyanate with 3-aminocrotonate and subsequent cyclization in a sodium hydroxide solution at elevated temperature and bromination in acetic acid [6] .
As an alternative preparation method, phosgene and ammonia can be reacted with sec-butylamine to form sec-butylurea, which in turn reacts with acetoacetic acid methyl ester to form 3-sec-butyl-6-methyluracil. Subsequent bromination leads to the formation of bromouracil [6] [7] .
Properties
Bromacil is a non-combustible solid substance without color and odor, which is very slightly soluble in water [1] . It decomposes on heating. Resistant to hydrolysis by acids and under the action of sunlight [8] .
Security
Care should be taken when spraying plants with bromacil, since it also stops photosynthesis in non-target plants, killing them. Bromacil should never be used in residential and recreational areas. Bromacil is slightly toxic to humans if swallowed or comes into contact with the remainder of the drug and is practically non-toxic by inhalation. The drug slightly irritates the mucous membranes of the eyes and very slightly irritates the skin. It is not a skin sensitizer [9] . In studies using laboratory animals, it was shown that bromacil is slightly toxic when administered orally or transdermally, as well as by inhalation, and was assigned to toxicity category IV (the lowest of the four categories) [3] . The herbicide should be stored in a cool, dry place and thorough hand washing is recommended after treatment.
Regarding exposure in the workplace, the National Institute of Labor Protection recommended that workers working with bromacil do not exceed an exposure of 1 mg (10 mg / m 3 ) for an average of eight hours [10] .
Toxicology
Bromacil is part of a group of chemicals that are absorbed in the intestine and excreted primarily in the urine . The half-life of bromacil in the soil is about 60 days, but in some conditions it can be 8 months [9] . Bromacil is available in the form of granules, liquid, water-soluble liquid and powder [4] . Since bromacil may be a carcinogen in humans and systemic toxicity may occur after intermediate exposure (from one week to several months), the US Environmental Protection Agency (EPA) assesses the risk to workers using several key possible scenarios. Bromacil is resistant to hydrolysis under normal environmental conditions [3] .
Usage
Bromacil is used primarily for spraying or in the form of an aerosol . Solid forms of bromacyl are used with the help of granule applicators and spreaders [3] .
Notes
- ↑ 1 2 3 4 5 Record of CAS RN 314-40-9 in the GESTIS Substance Database of the IFA .
- ↑ http://www.cdc.gov/niosh/npg/npgd0063.html
- ↑ 1 2 3 4 United States Environmental Protection Agency. "Bromacil." 1996, p. 1-11. Accessed October 9, 2012
- ↑ 1 2 3 Cornell University. "Bromacil." 1993, p. 1. Accessed October 9, 2012
- ↑ USDOE-Bonneville Power Administration. 2000, p. 1-9.
- ↑ 1 2 Eintrag zu Bromacil in der Hazardous Substances Data Bank , abgerufen am 1. März 2013.
- ↑ Thomas A. Unger. Pesticide Synthesis Handbook . - William Andrew, 1996 .-- P. 568. - ISBN 0-08095716-1 .
- ↑ Terence Robert Roberts, David Herd Hutson. Metabolic Pathways of Agrochemicals. Part 1. Herbicides and Plant Growth Regulators . - Royal Society of Chemistry, 1998. - P. 696. - ISBN 0-85404494-9 .
- ↑ 1 2 Washington State Department of Transportation. “Bromacil”. 2006, p. 1-4. Accessed October 9, 2012
- ↑ Centers for Disease Control and Prevention Bromacil . NIOSH Pocket Guide to Chemical Hazards (April 4, 2011). Date of treatment November 13, 2013.