4,5-Dichlor-3,6-dioxocyclohexa-1,4-dien-1,2-dicarbonitril Chemische Eigenschaften,Einsatz,Produktion Methoden
R-Sätze Betriebsanweisung:
R25:Giftig beim Verschlucken.
R29:Entwickelt bei Berührung mit Wasser giftige Gase.
R41:Gefahr ernster Augenschäden.
R37/38:Reizt die Atmungsorgane und die Haut.
R20/21:Gesundheitsschädlich beim Einatmen und bei Berührung mit der Haut.
R23/24/25:Giftig beim Einatmen, Verschlucken und Berührung mit der Haut.
S-Sätze Betriebsanweisung:
S22:Staub nicht einatmen.
S24/25:Berührung mit den Augen und der Haut vermeiden.
S37:Geeignete Schutzhandschuhe tragen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn möglich, dieses Etikett vorzeigen).
S36/37:Bei der Arbeit geeignete Schutzhandschuhe und Schutzkleidung tragen.
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S36/37/39:Bei der Arbeit geeignete Schutzkleidung,Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
Beschreibung
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) has a variety of applications. DDQ is a deprotection agent for ketals, acetals, and thioacetals. It is a useful electron transfer reagent for synthesis of quinolones and an oxidizing agent used to synthesize steroids. Additionally, DDQ is used with Ph3P to synthesize 1,2-benzisoxazoles.
Chemische Eigenschaften
yellow to orange powder
Verwenden
An oxidizing agent, especially in steroid synthesis.
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone is used as a reagent for oxidative couplings and cyclization reactions and dehydrogenation of alcohols, phenols and steroid ketones. It is also used in the synthesis of 1,2-benzisoxazoles. It is a useful electron-transfer reagent for synthesis of quinolines from imines and alkynes or alkenes.
synthetische
The first synthesis of 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) was described by J.Thiele and F.Guntber in 1906. However, no interest was shown in the compound until Linstead and co-workers discovered its extraordinary potency as a dehydrogenating agent. Its oxidation potential is greater than that of any other known quinone.
2,3-Dichloro-5,6-Dicyanobenzoquinone (DDQ). A New Preparation
Application
2,3-Dichloro-5,6-dicyano-p-benzoquinone (DDQ) can be used as:
A deprotecting reagent for a variety of compounds, such as thioacetals, acetals, and ketals.
An electron-transfer reagent for the synthesis of quinolines from imines and alkynes or alkenes.
An effective reagent for the benzylic and allylic CH functionalization.
An oxidizing agent for the synthesis of functionalized furans and benzofurans.
A reagent with Ph3P in an efficient synthesis of 1,2-benzisoxazoles.
Mechanism of action
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) has many applications in the oxidation of various organic compounds such as ketones, alcohols, phenols, aromatic compounds, heterocyclic structures, etc. Apart from that, the presence of two chlorine atoms and two nitrile groups on the benzoquinone ring may also behave as a potential chlorinating agent. Consequently, DDQ could act simultaneously as the chlorinating agent and the oxidant. It can also remove the protective functional groups during deprotections of different chemical entities. For dehydrogenation by DDQ, the mechanism includes the transfer of hydride to the quinone oxygen followed by the transfer of a proton to the phenolate ion[1].
Sicherheit(Safety)
DDQ reacts with water to release highly toxic hydrogen cyanide (HCN). A low-temperature and weakly acidic environment increases the stability of DDQ.
läuterung methode
Crystallise DDQ from CHCl3, CHCl3/*benzene (4:1), or *benzene and store it at 0o. [Pataki & Harvey J Org Chem 52 2226 1987, Beilstein 10 H 902, 10 II 635, 10 IV 3521.]
4,5-Dichlor-3,6-dioxocyclohexa-1,4-dien-1,2-dicarbonitril Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
