Citral

Bezeichnung:Citral

CAS-Nr5392-40-5

Englisch Name:Citral

CBNumberCB8364074

SummenformelC10H16O

Molgewicht152.23

MOL-Datei5392-40-5.mol

Synonyma

Citral

3,7-Dimethyl-2,6 octadienal

Lemonal

Citral physikalisch-chemischer Eigenschaften

Schmelzpunkt	<-10°C
Siedepunkt	229 °C (lit.)
Dichte	0.888 g/mL at 25 °C (lit.)
Dampfdichte	5 (vs air)
Dampfdruck	0.2 mm Hg ( 200 °C)
FEMA	2303 \| CITRAL
Brechungsindex	n20/D 1.488(lit.)
Flammpunkt	215 °F
storage temp.	2-8°C
Löslichkeit	0.42g/l
Aggregatzustand	Liquid
Farbe	colorless to light yellow
Geruch (Odor)	at 100.00 %. sweet lemon citral
Geruchsart	citrus
Explosionsgrenze	4.3-9.9%(V)
Wasserlöslichkeit	PRACTICALLY INSOLUBLE
Merck	14,2322
JECFA Number	1225
BRN	1721871
Expositionsgrenzwerte	ACGIH: TWA 5 ppm (Skin)
Stabilität	Stable. but readily isomerizes. Incompatible with alkalies, strong oxidizing agents, strong acids. Combustible. Air and light sensitive.
LogP	2.76 at 25℃
CAS Datenbank	5392-40-5(CAS DataBase Reference)
NIST chemische Informationen	Citral(5392-40-5)
EPA chemische Informationen	Citral (5392-40-5)

Sicherheit

Kennzeichnung gefährlicher	Xi
R-Sätze:	38-43
S-Sätze:	24/25-37
RIDADR	1760
WGK Germany	1
RTECS-Nr.	RG5075000
Selbstentzündungstemperatur	225 °C
TSCA	Yes
HS Code	2912 19 00
HazardClass	8
PackingGroup	III
Giftige Stoffe Daten	5392-40-5(Hazardous Substances Data)
Toxizität	LD50 orally in rats: 4.96 g/kg (Opdyke)

Gefahreninformationscode (GHS)

Citral Chemische Eigenschaften,Einsatz,Produktion Methoden

ERSCHEINUNGSBILD
HELLGELBE FLüSSIGKEIT MIT CHARAKTERISTISCHEM GERUCH.
CHEMISCHE GEFAHREN
Die Substanz zersetzt sich beim Verbrennen unter Bildung von reizenden Rauchen. Der Stoff kann polymerisieren beim Erhitzen.
ARBEITSPLATZGRENZWERTE
TLV nicht festgelegt.
MAK nicht festgelegt.
INHALATIONSGEFAHREN
Nur ungenügende Angaben vorhanden über die Geschwindigkeit, mit der eine gesundheitsschädliche Konzentration in der Luft beim Verdampfen bei 20°C erreicht wird.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION:
Die Substanz reizt die Haut.
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
Wiederholter oder andauernder Kontakt kann zu Hautsensibilisierung führen.
LECKAGE
Persönliche Schutzausrüstung: Chemikalienschutzanzug. Atemschutzfilter für organische Gase und Dämpfe. Zündquellen entfernen. Ausgelaufene Flüssigkeit in abgedeckten Behältern sammeln. Reste mit Sand oder inertem Absorptionsmittel aufnehmen und an einen sicheren Ort bringen. NICHT in die Umwelt gelangen lassen.
R-Sätze Betriebsanweisung:
R38:Reizt die Haut.
R43:Sensibilisierung durch Hautkontakt möglich.
S-Sätze Betriebsanweisung:
S24/25:Berührung mit den Augen und der Haut vermeiden.
S37:Geeignete Schutzhandschuhe tragen.
Aussehen Eigenschaften
C6H16O; 3,7-Dimethyl-2,6-octadienal. Hellgelbe Flüssigkeit mit Geruch nach Zitronen.
Gefahren für Mensch und Umwelt
Reizt die Haut.
Sensibilisierung durch Hautkontakt möglich.
Nicht mit Aluminium, Laugen und Säuren in Berührung bringen.
LD₅₀ (oral, Ratte): 4960 mg/kg.
Schutzmaßnahmen und Verhaltensregeln
Schutzhandschuhe als kurzzeitiger Spritzschutz.
Verhalten im Gefahrfall
Mit flüssigkeitsbindendem Material, z.B. Rench Rapid aufnehmen. Der Entsorgung zuführen. Nachreinigen.
Kohlendioxid, Pulver, Schaum.
Brennbar.
Erste Hilfe
Nach Hautkontakt: Mit reichlich Wasser abspülen.
Nach Augenkontakt: Mit reichlich Wasser bei geöffnetem Lidspalt mindestens 15 Minuten ausspülen. Sofort Augenarzt hinzuziehen.
Nach Einatmen: Frischluft.
Nach Verschlucken: Reichlich Wasser trinken lassen. Erbrechen auslösen. Arzt hinzuziehen.
Nach Kleidungskontakt: Kontaminierte Kleidung sofort entfernen.
Ersthelfer: siehe gesonderten Anschlag
Sachgerechte Entsorgung
Als halogenfreie, organische Lösemittelabfälle.
Chemische Eigenschaften
mobile light yellow liquid with a lemon-like smell
Chemische Eigenschaften
Citral has a strong, lemon-like odor and a characteristic bittersweet taste. Commercially, the product is a mixture of two geometric isomers—α-citral and β-citral, each exhibiting cis- and trans-isomers because of the position of the double bond.
Chemische Eigenschaften
Citral occurs as (2Z)- and (2E)-isomers (citral a and b, respectively) analogous to the corresponding alcohols, geraniol and nerol: geranial (citral a), bp2.7 kPa 118–119 °C, d20 0.8888, n20 D 1.4898; neral (citral b), bp2.7 kPa 120 °C, d20 0.8869, n20 D 1.4869. Natural citral is nearly always a mixture of the two isomers. It occurs in lemongrass oil (up to 85%), in Litsea cubeba oil (up to 75%), and in small amounts inmany other essential oils. The citrals are colorless to slightly yellowish liquids, with an odor reminiscent of lemon.
Since citral is an α,β-unsaturated aldehyde with an additional double bond, it is highly reactive and may undergo reactions such as cyclization and polymerization. Geraniol, citronellol, and 3,7-dimethyloctan-l-ol can be obtained from citral by stepwise hydrogenation. Citral can be converted into a number of addition compounds; the (Z)- and (E)-isomers can be separated via the hydrogen sulfite addition compounds.The condensation of citral with active methylene groups is used on an industrial scale in the synthesis of pseudoionones, which are starting materials for ionones and vitamins.
Occurrence
Reported found in apricot, clary sage, ginger, grape, grapefruit, lemon, lime, mandarin, orange, raspberry, tamarind, tangerine, tea and tomato.
Verwenden
Citral is an anti-microbial agent found in plants with antibacterial activity against some food pathogens. It is also a fragrance compound with a distinct lemon scent.
Verwenden
Citral is a liquid flavoring agent, light yellow in color with a citrus odor. it occurs in lemon and lemongrass oils. it is usually obtained from citral-containing oils by chemical means but may also be pre- pared synthetically. it is soluble in fixed oils, mineral oil, and pro- pylene glycol. it is moderately stable and should be stored in glass, tin, or resin-lined containers. it is used in flavors for lemon with applications in candy, baked goods, and ice cream at 20–40 ppm. it is also termed 2,6-dimethyl-octadian-2-6-al-8.
Verwenden
citral is a naturally occurring aroma compound used to provide a lemon-type fragrance. Citral is a constituent of lemon oil, lemongrass oil, lime oil, ginger oil, verbena oil, and other plant-derived C essential oils.
Definition
Commercial material is a mixture of α and β isomers.
synthetische
Since citral is used in bulk as a starting material for the synthesis of vitamin A, it is produced industrially on a large scale. Smaller quantities are also isolated from essential oils.
1) Isolation from essential oils: Citral is isolated by distillation from lemongrass oil and from L. cubeba oil. It is the main component of these oils. 2) Synthesis from geraniol: Currently, the most important synthetic procedures are vapor-phase dehydrogenation and oxidation of geraniol or geraniol–nerol mixtures. Catalytic dehydrogenation under reduced pressure using copper catalysts is preferred.
3) Synthesis from dehydrolinalool: Dehydrolinalool is produced on a large scale from 6-methyl-5-hepten-2-one and acetylene and can be isomerized to citral in high yield by a number of catalysts. Preferred catalysts include organic orthovanadates, organic trisilyl oxyvanadates, and vanadium catalysts with silanols added to the reaction system.
4) Synthesis from isobutene and formaldehyde: 3-Methyl-3-buten-l-ol, obtained from isobutene and formaldehyde, isomerizes to form 3-methyl- 2-buten-lol. However, it is also converted into 3-methyl-2-butenal by dehydrogenation and subsequent isomerization. Under azeotropic conditions in the presence of nitric acid, 3-methyl-2-buten-l-ol and 3-methyl-2-butenal form an acetal (shown as follows), which eliminates one molecule of 3-methyl-2-buten-l-ol at higher temperatures. The intermediate enol ether undergoes Claisen rearrangement followed by Cope rearrangement to give citral in excellent yield:
Today, this route is performed on a very large industrial scale in a continuous reactive distillation process.
Aroma threshold values
Detection at 1.0%: characterizing lemon-like, distilled lime peel, intense aldehydic citruslike.
Taste threshold values
Taste characteristics at 5 ppm in 5% sugar and 0.1% CA: characteristic lemon, peely, citrus, green floral juicy with woody and candy notes.
Synthesis Reference(s)
Journal of the American Chemical Society, 101, p. 7131, 1979 DOI: 10.1021/ja00517a088
Tetrahedron Letters, 35, p. 4007, 1994 DOI: 10.1016/S0040-4039(00)76726-8
Allgemeine Beschreibung
A clear yellow colored liquid with a lemon-like odor. Less dense than water and insoluble in water. Toxic by ingestion. Used to make other chemicals.
Air & Water Reaktionen
Insoluble in water.
Reaktivität anzeigen
Citral is an aldehyde. Aldehydes are frequently involved in self-condensation or polymerization reactions. These reactions are exothermic; they are often catalyzed by acid. Aldehydes are readily oxidized to give carboxylic acids. Flammable and/or toxic gases are generated by the combination of aldehydes with azo, diazo compounds, dithiocarbamates, nitrides, and strong reducing agents. Aldehydes can react with air to give first peroxo acids, and ultimately carboxylic acids. These autoxidation reactions are activated by light, catalyzed by salts of transition metals, and are autocatalytic (catalyzed by the products of the reaction). The addition of stabilizers (antioxidants) to shipments of aldehydes retards autoxidation. Citral can react with alkalis and strong acids. Citral can readily isomerize.
Hazard
Questionable carcinogen.
Brandgefahr
Citral is combustible.
Flammability and Explosibility
Non flammable
Kontakt-Allergie
Citral is an aldehyde fragrance and flavoring ingredient, a blend of isomers cis (Neral) and trans (geranial). As a fragrance allergen, citral has to be mentioned by name in cosmetics within the EU.
Sicherheitsprofil
Moderately toxic by intraperitoneal route. Mildly toxic by ingestion. Experimental reproductive effects. A severe human and experimental skin irritant. Mutation data reported. Combustible liquid. When heated to decomposition it emits acrid smoke and irritating fumes.
Synthese
Citral is usually isolated from the citral-containing oil by chemical means or by chemical synthesis (from β-pinene, isoprene, etc.).

Citral Upstream-Materialien And Downstream Produkte

Citral Anbieter Lieferant Produzent Hersteller Vertrieb Händler.

5392-40-5, Citral Verwandte Suche:

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