5-bromo-1H-indazol-3-ol cas 7364-27-4 5-Bromo-3-hydroxy (1H)indazole white to yellow powder support customized synthesis

The corresponding chemical substance for CAS 7364-27-4 is 2,4-dichlorophenoxyacetic acid, which is commonly referred to as 2,4-D.
It is a very important organic compound, and is mainly known for its uses as an herbicide and a plant growth regulator.
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Basic Information

· Chemical name: 2,4-Dichlorophenoxyacetic acid
· English name: 2,4-Dichlorophenoxyacetic acid
· CAS number: 7364-27-4
· Molecular formula: C₈H₆Cl₂O₃
· Molecular weight: 221.04 g/mol
· Appearance: White to yellow crystals or powder.
· Solubility: Slightly soluble in water, easily soluble in most organic solvents (such as ethanol, ether, acetone).
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Main purpose
1. Herbicides
· This is the most well-known and primary application of 2,4-D. It is a selective systemic translocating hormone-based herbicide.
· Mechanism of action: It mimics the effects of natural plant auxins (such as indoleacetic acid), but at excessive doses, it can disrupt the normal growth of plants, causing abnormal growth, distortion, and ultimately death.
· Selectivity: It is highly effective against broadleaf weeds (dicotyledonous plants), but relatively safe for grass family plants (such as lawn grass, wheat, corn, rice, etc.). Therefore, it is widely used in:
· Grain fields (wheat, barley, corn, rice)
· Lawns and golf courses
· Pastures and woodlands
· Sugar cane fields
2. Plant growth regulators
· At very low concentrations, 2,4-D can be used to promote plant growth, prevent early fruit drop (such as citrus fruits), and promote root formation, etc. However, the usage concentration needs to be very precise; otherwise, it will cause phytotoxicity.
3. Historical significance
· 2,4-D was the first successful commercial selective herbicide, introduced in the 1940s, triggering the "chemical herbicide revolution" in agriculture.
· It is also one of the main components of infamous Agent Orange (mixed with 2,4,5-T), and was used as a defoliant in the Vietnam War.
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Mechanism of action
2,4-D, as a synthetic auxin, once it enters the plant body, it will interfere with multiple physiological processes of the plant:
· Stimulate abnormal cell division and elongation, causing the stem to twist and swell.
· Damage the vascular system (especially the phloem), hindering nutrient transportation.
· Lead to the inhibition of root growth.
· Eventually cause the plant to grow stunted and deformed, and even die.
Grass plants are less sensitive to this because they can break down their metabolites more quickly, and their leaf morphology (upright, narrow, with thick waxy layer) is less likely to adhere and absorb the pesticide solution.
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Safety and Toxicity
The safety of 2,4-D is a topic that has received extensive attention and regulation.
· Toxicity classification: It falls within the range of low to moderate toxicity.
· Impact on human health:
· Acute exposure: It can irritate the eyes, skin, and respiratory tract. Ingestion may cause nausea, vomiting, diarrhea, headache, and confusion.
· Chronic exposure: Some epidemiological studies have linked it to an increased risk of certain cancers (such as non-Hodgkin's lymphoma), but the evidence is not yet conclusive. The International Agency for Research on Cancer classifies it as Group 2B ("possibly carcinogenic to humans").
· Environmental fate:
· It can be degraded by microorganisms in soil, with a half-life typically ranging from a few days to a few weeks.
· It is toxic to aquatic organisms, especially to fish and aquatic invertebrates.
· Due to its water solubility, it may contaminate water sources through runoff.
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Regulation and Usage Restrictions
Due to its potential risks, regulatory agencies around the world have strict regulations on the use of 2,4-D:
· China: 2,4-D is a registered pesticide that is permitted for use. However, there are strict regulations regarding its application scope, dosage, safety interval, and maximum residue limit.
· United States: The Environmental Protection Agency of the United States strictly regulates it and conducts regular re-evaluations.
· European Union: Certain salt and ester formulations of 2,4-D have been banned or restricted for use.
Important reminder: When using any product containing 2,4-D, you must strictly follow the instructions on the product label and wear appropriate personal protective equipment.
Summary

CAS 7364-27-4 (2,4-D) is a chemical substance of great significance in the history of agriculture. As an efficient and selective herbicide, it has made a significant contribution to increasing global food production. However, its potential health and environmental risks require us to approach it with a scientific and prudent attitude and strictly adhere to the safety usage guidelines.