2,4-Dichlorbenzoesure

Bezeichnung:2,4-Dichlorbenzoesure

CAS-Nr50-84-0

Englisch Name:2,4-Dichlorobenzoic acid

CBNumberCB9255955

SummenformelC7H4Cl2O2

Molgewicht191.01

MOL-Datei50-84-0.mol

Synonyma

2,4-Dichlorbenzoesure

2,4-Dichlorbenzoesure physikalisch-chemischer Eigenschaften

Schmelzpunkt	157-160 °C (lit.)
Siedepunkt	200 °C
Dichte	1.4410 (rough estimate)
Brechungsindex	1.4590 (estimate)
storage temp.	Sealed in dry,Room Temperature
Löslichkeit	ethanol: soluble1g/10 mL, clear, colorless
pka	2.68±0.25(Predicted)
Aggregatzustand	Powder
Farbe	White to almost white
PH	2.8 (0.36g/l, H2O, 15℃)
Wasserlöslichkeit	0.36 g/L (15 ºC)
BRN	1868192
Stabilität	Stable. Incompatible with strong oxidizing agents.
CAS Datenbank	50-84-0(CAS DataBase Reference)
NIST chemische Informationen	2,4-Dichlorobenzoic acid(50-84-0)
EPA chemische Informationen	Benzoic acid, 2,4-dichloro- (50-84-0)

Sicherheit

Kennzeichnung gefährlicher	Xn,Xi
R-Sätze:	22-36/37/38
S-Sätze:	26-36-37/39-22
WGK Germany	3
RTECS-Nr.	DG6650000
Hazard Note	Irritant
TSCA	Yes
HS Code	29163900

Gefahreninformationscode (GHS)

2,4-Dichlorobenzoic acid Chemische Eigenschaften,Einsatz,Produktion Methoden

R-Sätze Betriebsanweisung:
R22:Gesundheitsschädlich beim Verschlucken.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
S-Sätze Betriebsanweisung:
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
S37/39:Bei der Arbeit geeignete Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
S22:Staub nicht einatmen.
Chemische Eigenschaften
white powder
Verwenden
2,4-Dichlorobenzoic acid is used as reagent during the synthesis of pyrimido[2?,1?:2,3]thiazolo[4,5-b]quinoxaline derivatives. It is also used as starting reagent during the synthesis of 1-(substituted)-1,4-dihydro-6-nitro-4-oxo-7-(sub-secondary amino)-quinoline-3-carboxylic acids.
Verwenden
2,4-Dichlorobenzoic Acid is a di-halogenated benzoic acid derivative and an intermediate in the synthesis of spirodiclofen (S682990), a tetronic acid acaricide fungicide used in controlling red mites.
Definition
ChEBI: A chlorobenzoic acid that is benzoic acid in which the ring hydrogens at positions 2 and 4 are substituted by chloro groups.
Allgemeine Beschreibung
White to slightly yellowish powder.
Air & Water Reaktionen
Insoluble in water.
Reaktivität anzeigen
2,4-Dichlorobenzoic acid is a halogenated carboxylic acid. Carboxylic acids donate hydrogen ions if a base is present to accept them. They react in this way with all bases, both organic (for example, the amines) and inorganic. Their reactions with bases, called "neutralizations", are accompanied by the evolution of substantial amounts of heat. Neutralization between an acid and a base produces water plus a salt. Carboxylic acids with six or fewer carbon atoms are freely or moderately soluble in water; those with more than six carbons are slightly soluble in water. Soluble carboxylic acid dissociate to an extent in water to yield hydrogen ions. The pH of solutions of carboxylic acids is therefore less than 7.0. Many insoluble carboxylic acids react rapidly with aqueous solutions containing a chemical base and dissolve as the neutralization generates a soluble salt. Carboxylic acids in aqueous solution and liquid or molten carboxylic acids can react with active metals to form gaseous hydrogen and a metal salt. Such reactions occur in principle for solid carboxylic acids as well, but are slow if the solid acid remains dry. Even "insoluble" carboxylic acids may absorb enough water from the air and dissolve sufficiently in 2,4-Dichlorobenzoic acid to corrode or dissolve iron, steel, and aluminum parts and containers. Carboxylic acids, like other acids, react with cyanide salts to generate gaseous hydrogen cyanide. The reaction is slower for dry, solid carboxylic acids. Insoluble carboxylic acids react with solutions of cyanides to cause the release of gaseous hydrogen cyanide. Flammable and/or toxic gases and heat are generated by the reaction of carboxylic acids with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Carboxylic acids, especially in aqueous solution, also react with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), to generate flammable and/or toxic gases and heat. Their reaction with carbonates and bicarbonates generates a harmless gas (carbon dioxide) but still heat. Like other organic compounds, carboxylic acids can be oxidized by strong oxidizing agents and reduced by strong reducing agents. These reactions generate heat. A wide variety of products is possible. Like other acids, carboxylic acids may initiate polymerization reactions; like other acids, they often catalyze (increase the rate of) chemical reactions.
Brandgefahr
Flash point data for 2,4-Dichlorobenzoic acid are not available; however, 2,4-Dichlorobenzoic acid is probably combustible.
läuterung methode
Crystallise the acid from aqueous EtOH (charcoal), then *benzene (charcoal). It can also be recrystallised from water. [Beilstein 9 IV 998.] It can be freed from isomeric acids (to <0.05%) via the (±)--methylbenzylamine salt as follows: dissolve the dichloro-acid (10g, 50.2mmol) in isopropanol (200mL), heat to 60o and add the (±)-benzylamine (5.49g, 45.3mmol), then stir it at 60o for 1hour. Cool the mixture to room temperature, filter the slurry, wash it with isopropanol (25mL) and dry it in vacuo at 40o overnight to give 79% of the salt with m 185.2o. Dissolve the salt (5g) in H2O (50mL) and MeOH (20mL), then heat to 60o and add concentrated HCl to pH <2.0. Cool the solution to room temperature add H2O (12mL), filter it, wash it with H2O (30mL) and dry it in vacuo at 40o overnight to give 94% of the acid with m 162.0o. [Ley & Yates Organic Process Research & Development 12 120 2008.]

2,4-Dichlorobenzoic acid Upstream-Materialien And Downstream Produkte

2,4-Dichlorbenzoesure Anbieter Lieferant Produzent Hersteller Vertrieb Händler.

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