22190-65-4

Upstream product

• 489-84-9 7-isopropyl-1,4-dimethyl-azulene 
• 98-88-4 benzoyl chloride 
• 22195-75-1 3-Tropylguaiazulen 
• 93-97-0 benzoic acid anhydride 
• 102560-55-4 (5-isopropyl-3,8-dimethyl-azulen-1-yl)-phenyl-acetonitrile 

Downstream Products

• 1251734-93-6 1-{3-[(3-benzoyl-7-isopropyl-4-methylazulen-1-yl)carbonyl]-7-isopropyl-4-methylazulen-1-yl}ethanone 
• 39665-56-0 2-Benzoylguajazulen 
• 39711-52-9 1-Benzoyl-7-isopropyl-3,4-dimethylazulen 
• 39665-57-1 2-Benzylguajazulen 

Relevant academic research and scientific papers

Spontaneous substitution of azulene-derived benzylic alcohols by thiols and its application to labeling/protection of biothiols

By mixing guaiazulene-3-methanol derivatives and thiols at room temperature, benzylic substitution of the alcohol proceeded to yield the corresponding sulfide. Because of the blue color of the guaiazulene derivative, this spontaneous reaction was used for labeling of paper-immobilized biothiols. By treatment with tris(2-carboxyethyl)phosphine hydrochloride, the guaiazulene-3-ylmethyl part of the sulfide could be removed and the original thiol recovered. Based on these findings, a guaiazulene-3-methanol derivative was used as a protective group for the synthesis of cysteine derivatives.

Synthesis of Azulen-1-yl Ketones via Oxidative Cleavage of C-C Multiple Bonds in N-Sulfonyl Enamides and 1-Alkynes under Air and Natural Sunlight

A synthetic method to prepare azulen-1-yl ketones was developed via oxidative cleavage of the C-C double bond in the reaction of easily obtainable N-sulfonyl enamides with Cs2CO3 under air and natural sunlight and in the absence of a photosensitizer. Oxidative cleavage of C-C triple bonds was also demonstrated for the synthesis of azulen-1-yl ketones via a tandem Cu-catalyzed [3 + 2] cycloaddition, Rh-catalyzed arylation, photooxygenation, and ring-opening reaction in one pot under air and natural sunlight.

Report on an unusual cascade reaction between azulenes and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (=4,5-dichloro-3,6-dioxocyclohexa-1,4- diene-1,2-dicarbonitrile; DDQ)

The oxidation of 1-(3,8-dimethylazulen-1-yl)alkan-1-ones 1 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (=4,5-dichloro-3,6-dioxocyclohexa-1,4- diene-1,2-dicarbonitrile; DDQ) in acetone/H2O mixtures at room temperature does not only lead to the corresponding azulene-1-carboxaldehydes 2 but also, in small amounts, to three further products (Tables 1 and 2). The structures of the additional products 3-5 were solved spectroscopically, and that of 3a also by an X-ray crystal-structure analysis (Fig. 1). It is demonstrated that the bis(azulenylmethyl)-substituted DDQ derivatives 5 yield on methanolysis or hydrolysis precursors, which in a cascade of reactions rearrange under loss of HCl into the pentacyclic compounds 3 (Schemes 4 and 7). The found 1,1′-[carbonylbis(8-methylazulene-3,1-diyl)]bis[ethanones] 4 are the result of further oxidation of the azulene-1-carboxaldehydes 2 to the corresponding azulene-1-carboxylic acids (Schemes 9 and 10).