34305-47-0

Usage

Purification Methods

Purify it by chromatography on alumina and eluting with pentane, also by reverse phase (ODS) HPLC using MeCN as solvent. It is stable at room temperature [Kjell et al. J Am Chem Soc 108 4111 1986, Abelt et al. J Am Chem Soc 107 4148 1985]. The 1H NMR in CCl4 has 3.18 (4H), 6.17 (t J 1.5Hz, 2H), 7.60 (t J 1.5Hz 2H).

InChI:InChI=1/C10H8/c1-2-4-6-5(3-1)7-9-8(6)10(7)9/h1-4,7-10H

Upstream product

• 122608-26-8 2a,2b,6b,6c-Tetrahydro-1-oxa-2-thiabenzocyclopropapentalene 2-Oxide 
• 122608-25-7 1,1a,6,6a-Tetrahydro-1,6-epithiocyclopropindene 7,7-Dioxide 
• 102505-34-0 diazabenzosemifullvalene 
• 275-51-4 azulene 

Downstream Products

• 91-20-3 naphthalene 
• 2471-84-3 1-methylene-1H-indene 
• 22187-13-9 1,4-dihydro-1,4-epoxyanthracene 
• 188971-44-0 naphthoylnaphthvalene 

Relevant academic research and scientific papers

Thermal isomerization of azulene. Single-pulse shock tube investigation

The thermal isomerization of azulene was studied behind reflected shocks in a pressurized driver single-pulse shock tube. The temperature range covered was 1050-1400 K at overall densities of ～2.5 × 10-5 mol/cm3. The main reaction of azulene under these conditions is a unimolecular isomerization to naphthalene, but it also isomerizes, although at a much lower rate, to another isomer. The suggested tetracyclic triene intermediate structure for the uzulene-naphthalene isomerization can lead also to transition states that can describe isomerizations to 1-methylene-1H-indene and 1,2,3-metheno-1H-indene,2,3-dihydro. Small quantities of C2H2, C4H2, C6H6, and C6H5-C≡CH were also found in the post-shock samples, particularly at high temperatures. The Arrhenius parameters of the two high pressure limit rate constants for the isomerization processes are: azulene ??? naphthalene, k1 = 1012.93 exp(-62.8 × 103/RT) s-1 azulene → second isomer, k2 = 1012.42 exp(-69.5 × 103/RT) s-1 A discussion of the mechanism for these isomerization processes is presented. * Author to whom correspondence should be addressed.

PHOTOLYSIS AND THERMAL DECAY OF THE SULFUR DIOXIDE ADDUCTS OF BENZOBENZVALENE

Benzobenzvalene 1 is shown to add SO2 with formation of a strained sulfone 2 and an isomeric γ-sultine 3.Photochemically (254 nm) the two adducts interconvert.Moreover, SO2 is extruded during the irradiation of 2 or 3 with regeneration of 1 and formation of naphthalene.This result is interpreted in terms of a reversible homolytic cleavage leading to an intermediate sulfinyloxy biradical 5 and subsequent formation of the benzoprefulvene biradical 6.The pyrolysis of 2 and 3, in the gas phase (FVP) and in solution, 1H-indene-1-carboxaldehyde 8 and naphthalene.The key step of this thermal reaction is shown to consist of a cycloreversion giving an intermediate sulfene 9.This can be trapped with N-phenyl maleimide (NPMI).Key structures are ascertained by X-ray analysis.

155. The Photoreversible Addition of Sulfur Dioxide to Benzobenzvalene: A New Approach to the Benzoprefulvene Biradical

Benzobenzvalene (naphthvalene; 1) is shown to add SO2 to a lateral bicyclobutane bond with formation of a sulfone 2 and a 'γ-sultine' 3.The structure of the latter is unambiguously established by X-ray diffraction.Both adducts extrude SO2 upon direct photolysis at 254 nm and regenerate 1 accompanied by naphthalene in a 1:3 ratio.This result is interpreted in terms of a reversible homolytic cleavage leading, for both, 2 and 3, to the same sulfinyloxy biradical 5, which by loss of SO2 gives the benzoprefulvene biradical 6.The latter in its singlet state undergoes ring closure to 1, or it opens to give naphthalene.

Die Synthese und der thermische Zerfall des 1,2-Diazabenzosemibullvalens und dessen Beziehung zur Thermolyse des Benzobenzvalens

The -photoadduct of naphthalene and 4-phenyl-4H-1,2,4-triazol-3,5-dione (PTAD) was subjected to a triplet-sensitized di-?-methane rearrangement.Hydrolysis of the resulting urazol 15 gave a stable semicarbazide 16 which by nickel-peroxide oxidation gave 1,2-diazabenzosemibullvalene (10).At 40 deg C, the latter decays in CHCl3 solution to produce benzofulvene (2) as the principal product, accompanied by benzobenzvalene (1) and small amounts of naphthalene.This decay reaction is rationalized in terms of a 1,3-dipolar cycloreversion which is followed by denitrogenation to give indenyl carbene (9).The thermolysis of 1 in solution is believed to produceed via the same carbene.At present, these findings provide only a partial answer to the benzobenzvalene enigma (i.e., in solution at 150 deg C, 1 gives 2, but in the gas-phase at 300 deg C, 1 yields naphthalene).MeOH is shown to add readily to 10 in a homologous Michael addition.