21405-51-6

Basic information

• Product Name: 3,5-dichlorocyclohexa-3,5-diene-1,2-dione
• Synonyms: 3,5-Cyclohexadiene-1,2-dione, 3,5-dichloro-; 3,5-Dichloro-3,5-cyclohexadiene-1,2-dione
• CAS NO: 21405-51-6
• Molecular Formula: C₆H₂Cl₂O₂
• Molecular Weight: 176.9849
• Mol File: 21405-51-6.mol
• Article Data: 3

Chemical Properties

• Boiling Point: 201.9°C at 760 mmHg
• Flash Point: 79.2°C
• Density: 1.56g/cm³
• Vapor Pressure: 0.301mmHg at 25°C
• Refractive Index: 1.568
• CAS DataBase Reference: 3,5-dichlorocyclohexa-3,5-diene-1,2-dione(CAS DataBase Reference)
• NIST Chemistry Reference: 3,5-dichlorocyclohexa-3,5-diene-1,2-dione(21405-51-6)
• EPA Substance Registry System: 3,5-dichlorocyclohexa-3,5-diene-1,2-dione(21405-51-6)

Safety Data

• Hazardous Substances Data: 21405-51-6(Hazardous Substances Data)

Upstream product

• 13673-92-2 3,5-dichlorocatechol 
• 591-35-5 3,5-dichlorophenol 
• 88-06-2 2,4,6-Trichlorophenol 

Downstream Products

• 13673-92-2 3,5-dichlorocatechol 

Relevant articles and documents

Dearomatization of Electron-Deficient Phenols to ortho-Quinones: Bidentate Nitrogen-Ligated Iodine(V) Reagents

Despite their broad utility, the synthesis of ortho-quinones remains a significant challenge, in particular, access to electron-deficient derivatives remains an unsolved problem. Reported here is the first general method for the synthesis of electron-deficient ortho-quinones by direct oxidation of phenols. The reaction is enabled by a novel bidentate nitrogen-ligated iodine(V) reagent, a previously unexplored class of compounds which we have termed Bi(N)-HVIs. The reaction is extremely general and proceeds with excellent regioselectivity for the ortho over para isomer. Functionalization of the ortho-quinone products was examined, resulting in a facile one-pot synthesis of catechols, as well as the incorporation of a variety of heteroatom nucleophiles. This method represents the first synthetic application of Bi(N)-HVIs and demonstrates their potential as a platform for the further development of highly reactive, but also highly tunable, I(V) reagents.

Reactions of polar dienes with o-quinones

The behaviour of various types of polar dienes towards halogenated ortho quinones has been investigated in a number of representative cases.As compared to the commonly used para analogues, o-quinones provide a wide range of products that indicate a keener response to the nature, number, and position of substituents on both reactants. 3-Halogenated-o-naphthoquinones 1 and 2 react smoothly with a representative vinologous ketene acetal 3, vinylketene acetals 4 and 5, and a monooxygenated diene 6 to provide variously substituted phenanthrenequinones 7-11.Only monooxygenated dienes on the other hand add to o-benzoquinones 14-16 and give convenient syntheses of the corresponding o-naphthoquinones 18-20.Key words: cycloaddition, o-naphthoquinones, phenanthrenequinones, regiospecificity.